Method and apparatus for transmitting and receiving sidelink synchronization signal in wireless communication system

ABSTRACT

A method of transmitting, by a first user equipment (UE), a sidelink synchronization signal to a second UE in a wireless communication system ay include determining values of NID(1) and NID(2) corresponding to a sidelink identifier (SLID) value based on a number of types of a physical layer sidelink synchronization identity set and a number of sequences included in each type of the physical layer sidelink synchronization identity set; generating a sidelink primary synchronization signal (PSS) sequence and a sidelink secondary synchronization signal (SSS) sequence based on a first primitive polynomial, a second primitive polynomial, and a cyclic shift (CS) value; and mapping, on physical resources, and thereby transmitting the sidelink PSS sequence and the sidelink SSS sequence.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. application Ser. No.17/167,350, filed on Feb. 4, 2021, which is a continuation of pendingPCT International Patent Application No. PCT/KR2019/010173, filed onAug. 9, 2019, which claims priority from and the benefit of KoreanPatent Application No. 10-2018-0093879, filed on Aug. 10, 2018, each ofwhich is hereby incorporated by reference in its entirety.

BACKGROUND 1. Field

The present disclosure relates to a method and apparatus fortransmitting and receiving a sidelink synchronization signal in awireless communication system, and more particularly, to a method andapparatus for setting and generating a sequence of a sidelinksynchronization signal in a new radio (NR) wireless communication systemsupporting various numerologies and transmitting or receiving asynchronization signal on a sidelink.

2. Discussion of the Background

A 3rd generation partnership project (3GPP) new radio (NR) system maysupport various numerologies with respect to a time-frequency resourceunit standard into consideration of various scenarios, servicerequirements, potential system compatibility, etc., to meet requirementsfor 5-th generation (5G) communication. Also, the NR system may supporttransmission of a physical signal or a physical channel through aplurality of beams to outperform poor channel environments, such as highpathloss, phase noise, and frequency offset, occurring on a high carrierfrequency. Through this, the NR system may support applications, suchas, for example, enhanced Mobile Broadband (eMBB), massive Machine TypeCommunications (mMTC), ultra Machine Type Communications (uMTC), UltraReliable and Low Latency Communications (URLLC), and the like.

Vehicle-to-X; Vehicle-to-everything (V2X) communication refers to acommunication method of exchanging or sharing information, such astraffic conditions, through communication with other vehicles and/orroad infrastructures during driving. V2X may include, for example,vehicle-to-vehicle (V2V) that refers to communication between vehicles,vehicle-to-pedestrian (V2P) that refers to communication between avehicle and a user equipment (UE) carried by a pedestrian user, andvehicle-to-infrastructure/network (V2I/N) that refers to communicationbetween a vehicle and a roadside unit (RSU)/network. Also, the V2Xcommunication may include a method of using a PC5 link (or a sidelink)that is a device-to-device (D2D) communication interface, a method ofusing an Uu link (or an uplink and a downlink) that is a communicationinterface between a base station and a UE, or a method of using all ofthe PC5 link and the Uu link.

5G sidelink technology is under discussion for incorporation of new anddiverse services, such as automatic driving or remote driving, throughperformance improvement of ultra high reliability and/or ultra lowlatency, in 5G mobile communication. Basically, a communication protocolon a 5G sidelink requires acquiring a synchronization on a sidelink.Definition of a synchronization reference on the 5G sidelink and settingand generation of a synchronization signal sequence according to thesynchronization reference are not determined in detail so far.

SUMMARY

An aspect of the present disclosure provides a method and apparatus fordefining a sidelink synchronization reference, and setting andgenerating a synchronization signal sequence according to the sidelinksynchronization reference.

Another aspect of the present disclosure provides a method and apparatusfor generating and transmitting and receiving an M-sequence basedsynchronization signal sequence with respect to each of a sidelinkprimary synchronization signal (PSS) and a sidelink secondarysynchronization signal (SSS).

Another aspect of the present disclosure provides a method and apparatusfor setting and generating a sidelink synchronization signal forimproving a performance of distinguishing a downlink synchronizationsignal.

It will be appreciated by persons skilled in the art that the objectsthat could be achieved with the present disclosure are not limited towhat has been particularly described hereinabove and the above and otherobjects that the present disclosure could achieve will be more clearlyunderstood from the following detailed description.

According to an aspect of the present disclosure, there is provided amethod of transmitting, by a first user equipment (UE), a sidelinksynchronization signal to a second UE in a wireless communicationsystem, the method including: determining values of N_(ID) ⁽¹⁾ andN_(ID) ⁽²⁾ corresponding to a sidelink identifier (SLID) value based ona number of types of a physical layer sidelink synchronization identityset and a number of sequences included in each type of the physicallayer sidelink synchronization identity set; generating a sidelinkprimary synchronization signal (PSS) sequence by applying a firstinitialization value to a first primitive polynomial and applying acyclic shift (CS) to the sidelink PSS sequence based on the value ofN_(ID) ⁽²⁾; generating a sidelink secondary synchronization signal (SSS)sequence by applying a second initialization value to each of the firstprimitive polynomial and a second primitive polynomial, and applying CSto the sidelink SSS sequence based on the values of N_(ID) ⁽¹⁾ andN_(ID) ⁽²⁾; and mapping, on physical resources, and thereby transmittingthe sidelink PSS sequence to which the CS is applied and the sidelinkSSS sequence to which the CS is applied. At least one of the firstprimitive polynomial, the second primitive polynomial, a CS value forthe sidelink PSS sequence, and a CS value for the sidelink SSS sequenceis applied to be distinguished from at least one of a first primitivepolynomial and a second primitive polynomial applied to a downlink PSSor a downlink SSS, a CS value for a downlink PSS sequence, and a CSvalue for a downlink SSS sequence.

The features briefly summarized above with respect to the presentdisclosure are provided as an example only to explain the detaileddescription and are not construed to limit the scope of the presentdisclosure.

According to the present disclosure, there may be provided a method andapparatus for setting and generating a synchronization signal sequenceaccording to a sidelink synchronization reference.

Also, according to the present disclosure, there may be provided amethod and apparatus for generating and transmitting and receiving anM-sequence based synchronization signal sequence with respect to each ofa sidelink primary synchronization signal (PSS) and a sidelink secondarysynchronization signal (SSS).

Also, according to the present disclosure, there may be provided amethod and apparatus for setting and generating a sidelinksynchronization signal for improving a performance of distinguishing adownlink synchronization signal.

Also, according to the present disclosure, it is possible to reduce acomplexity of generating a sidelink synchronization signal and tomaximize a performance of distinguishing a downlink synchronizationsignal using a primitive polynomial or a cyclic shift value with respectto the sidelink synchronization signal.

Effects which can be acquired by the disclosure are not limited to theabove described effects, and other effects that have not been mentionedmay be clearly understood by those skilled in the art from the followingdescription.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 , FIG. 2 , and FIG. 3 illustrate examples of describing avehicle-to-everything (V2X) scenario according to the presentdisclosure;

FIG. 4 illustrates an example of a service provided based on a sidelink.

FIG. 5 illustrates an example of a downlink synchronization signal in awireless communication system.

FIG. 6 illustrates an example of a transmission through a plurality ofbeams in a synchronization signal transmission according to the presentdisclosure.

FIG. 7 illustrates an example of a structure of a synchronization signalframe in the case of considering a transmission through a plurality ofbeams in a synchronization signal transmission according to the presentdisclosure.

FIG. 8 illustrates an example of a structure of a synchronization signal(SS) block according to the present disclosure.

FIG. 9 illustrates an example of a sidelink synchronization referenceaccording to the present disclosure.

FIG. 10 is a flowchart illustrating an example of a method oftransmitting a sidelink synchronization signal sequence according to thepresent disclosure.

FIG. 11 is a flowchart illustrating an example of a method of receivinga sidelink synchronization signal sequence according to the presentdisclosure.

FIG. 12 is a diagram illustrating a configuration of a first terminaldevice according to the present disclosure.

FIG. 13 is a diagram illustrating a configuration of a second terminaldevice according to the present disclosure.

DETAILED DESCRIPTION OF THE ILLUSTRATED EMBODIMENTS

Hereinafter, examples of the present disclosure will be described indetail so that those skilled in the art can easily carry out theexamples referring to the accompanying drawings. However, the presentdisclosure may be embodied in many different forms and is not limited tothe examples described herein.

In the following description of the examples of the present disclosure,a detailed description of known functions and configurationsincorporated herein will be omitted when it may make the subject matterof the present disclosure unclear. Parts not related to the descriptionof the present disclosure in the drawings are omitted, and similar partsare denoted by similar reference numerals.

In the present disclosure, when an element is referred to as being“connected”, “coupled”, or “connected” to another element, it isunderstood to include not only a direct connection relationship but alsoan indirect connection relationship. Also, when an element is referredto as “containing” or “having” another element, it means not onlyexcluding another element but also further including another element.

In the present disclosure, the terms first, second, and so on are usedonly for the purpose of distinguishing one element from another, and donot limit the order or importance of the elements unless specificallymentioned. Thus, within the scope of this disclosure, the firstcomponent in an example may be referred to as a second component inanother example, and similarly a second component in an example may bereferred to as a second component in another example.

In the present disclosure, components that are distinguished from oneanother are intended to clearly illustrate each feature and do notnecessarily mean that components are separate. That is, a plurality ofcomponents may be integrated into one hardware or software unit, or asingle component may be distributed into a plurality of hardware orsoftware units. Accordingly, such integrated or distributed examples arealso included within the scope of the present disclosure, unlessotherwise noted.

In the present disclosure, the components described in the variousexamples do not necessarily mean essential components, but some may beoptional components. Accordingly, examples consisting of a subset of thecomponents described in an example are also included within the scope ofthis disclosure. Also, examples that include other components inaddition to the components described in the various examples are alsoincluded in the scope of the present disclosure. Further, thedescription described herein is related to a wireless communicationnetwork, and an operation performed in a wireless communication networkmay be performed in a process of controlling a network and transmittingdata by a system that controls a wireless network, e.g., a base station,or may be performed in a user equipment connected to the wirelesscommunication network.

It is apparent that various operations performed for communication witha terminal in a network including a base station and a plurality ofnetwork nodes may be performed by the base station or by other networknodes in addition to the base station. Here, the term ‘base station(BS)’ may be interchangeably used with other terms, for example, a fixedstation, a Node B, eNodeB (eNB), gNodeB (gNB), and an access point (AP).Also, the term ‘terminal’ may be interchangeably used with other terms,for example, user equipment (UE), a mobile station (MS), a mobilesubscriber station (MSS), a subscriber station (SS), and a non-APstation (non-AP STA).

Herein, transmitting or receiving a channel includes a meaning oftransmitting or receiving information or a signal through thecorresponding channel. For example, transmitting a control channelindicates transmitting control information or a signal through thecontrol channel. Likewise, transmitting a data channel indicatestransmitting data information or a signal through the data channel.

In the following, for clarity of description, term of descriptionrelated thereto is made below.

D2D: Device to Device (communication)

GNSS: Global Navigation Satellite System

RSU: Road Side Unit

SL: Sidelink

SLSS: Sidelink Synchronization Signal

SCI: Sidelink Control Information

PSSCH: Physical Sidelink Shared Channel

PSBCH: Physical Sidelink Broadcast Channel

PSCCH: Physical Sidelink Control Channel

PSDCH: Physical Sidelink Discovery Channel

ProSe: (Device to Device) Proximity Services

PSSID(SLID): Physical-layer Sidelink Synchronization Identity (SidelinkIdentity)

n_(ID) ^(SA): Sidelink Group Destination Identity

N_(ID) ^(SL): Physical Layer Sidelink Synchronization Identity

SA: Scheduling assignment

TB: Transport Block

TTI: Transmission Time Interval

RB: Resource Block

V2V: Vehicle to Vehicle

V2P: Vehicle to Pedestrian

V2I/N: Vehicle to Infrastructure/Network

Herein, a 5G system may be defined to include any of existing Long TermEvolution (LTE) based systems as well as a new radio (NR) system. Thatis, the 5G system may include a case in which LTE based wireless accesstechnology and NR wireless access technology are applied together aswell as a case in which the NR wireless access technology alone isapplied. Also, 5G sidelink technology may include all of sidelinktechnology to which NR alone is applied and sidelink technology to whichLTE and NR are applied together.

In V2X communication, control information transmitted from a UE toanother UE may be scheduling assignment (SA). If the aforementionedcontrol information is used for sidelink communication, the controlinformation may be SCI. Here, if the control information is transmittedthrough a sidelink, the control information may be transmitted throughthe aforementioned PSCCH that is a channel used to transmit controlinformation in the sidelink.

Also, data transmitted from a UE to another UE may be configured basedon a unit of a transport port (TB). Here, if the data is transmittedthrough a sidelink, the data may be transmitted through theaforementioned PSSCH that is a channel used to transmit data.

Herein, an operation mode may be defined based on a resource allocationmethod for transmitting data and control information for V2Xcommunication or direct link (e.g., D2D, ProSe, or SL) communication.

An base station (BS) resource scheduling mode (eNodeB resourcescheduling mode) may be a mode in which a BS (eNodeB) or a relay nodeschedules resources used for a UE to transmit V2X (or direct link)control information and/or data. Through this, the UE may transmit theV2X (or direct link) control information and/or data. This mode mayrefer to the BS resource scheduling mode.

For example, the BS or the relay node may provide, to a sidelink (ordirect link) transmitting UE, scheduling information about resourcesused to transmit sidelink (or direct ink) control information and/ordata through downlink control information (DCI). Therefore, the sidelink(or direct link) transmitting UE may transmit the sidelink (or directlink) control information and data to a sidelink (or direct link)receiving UE, and the sidelink (or direct link) receiving UE may receivesidelink (or direct link) data based on the sidelink (or direct link)control information.

Meanwhile, a UE autonomous resource selection mode may be a mode inwhich a UE autonomously selects resources used to transmit controlinformation and data and such resource selection may be determinedthrough sensing of the UE from a resource pool (i.e., a set of resourcecandidates). Through this, the UE may transmit control information anddata. This mode may refer to the UE autonomous resource selection mode.

For example, the sidelink (or direct link) transmitting UE may transmitsidelink (or direct link) control information and data to the sidelink(or direct link) receiving UE using its selected resource, and thesidelink (or direct link) receiving UE may receive sidelink (or directlink) data based on sidelink (or direct link) control information.

Here, for example, the aforementioned BS resource scheduling mode may bereferred to as Mode 1 in sidelink (or direct link) communication for D2Dand the like. Also, the BS resource scheduling mode may be referred toas Mode 3 in sidelink communication for V2X and the like. Also, the UEautonomous resource selection mode may be referred to as Mode 2 insidelink (or direct link) communication for D2D and the like. Also, theUE autonomous resource selection mode may be referred to as Mode 4 insidelink communication for V2X and the like.

Also, although the following description is made based on V2Xcommunication for clarity of description, it is provided as an exampleonly. For example, the present disclosure may apply alike tocommunication based on a direct link such as D2D, ProSe, and the like,and the present disclosure is not limited thereto.

Also, for example, V2X may be a general term for V2V, V2P, and V2I/N.Here, each of V2V, V2P, and V2I/N may be defined as the following Table1 connected with LTE (Long Term Evolution).

TABLE 1 V2V LTE or NR based communication between a vehicle and anothervehicle V2P LTE or NR based communication between a vehicle and a devicecarried by an individual (e.g., a terminal carried by a pedestrian, acyclist, a driver, or a passenger) V2I/N LTE or NR based communicationbetween a vehicle and a roadside unit(RSU)/network The RSU refers to asuspended social infrastructure entity that supports V2X applicationsand may exchange messages with other independent entities that supportV2X applications. The RSU is a logical independent entity integratedwith a V2X application logic having functions of a BS (in this case,referable as a eNB-type RSU) or a UE (in this case, referable as aUE-type RSU).

Also, V2X communication may include PC-5 based communication that is aninterface for sidelink communication, for this, as the D2D communicationlink (e.g., direct interface between a Device and a Device supportingthe ProSe system). For V2X operation, various scenarios such as thefollowing Table 2, Table 3, and Table 4, referring FIG. 1 , FIG. 2 , andFIG. 3 , are considered.

For example, the following Table 2 and FIG. 1 may refer to a scenariofor supporting a V2X operation based on only a PC5 interface (or SL).Here, (a) of FIG. 1 illustrates an example of a V2V operation, (b) ofFIG. 1 illustrates an example of a V2I operation, and (c) of FIG. 1illustrates an example of a V2P operation.

TABLE 2 Scenario that supports a V2X operation operating based on onlyPC5 In this scenario, a UE transmits a V2X message to a plurality of UEspresent in a local area through a sidelink. With respect to V2I, atransmitter UE or receiver UE(s) may be a UE-type roadside unit (RSU).With respect to V2P, a transmitter UE or receiver UE(s) may be apedestrian UE.

Meanwhile, the following Table 3 and FIG. 2 may refer to a scenario forsupporting a V2X operation based on only a Uu interface (i.e., aninterface between a UE and a BS). Here, (a) of FIG. 2 illustrates anexample of a V2V operation, (b) of FIG. 2 illustrates an example of aV2I operation, and (c) of FIG. 2 illustrates an example of a V2Poperation.

TABLE 3 Scenario that supports a V2X operation operating based on onlyUu interface In this scenario, With respect to V2V and V2P, a UEtransmits a V2X message to BS through an uplink, and the BS transmitsthe V2X message to a plurality of UEs present in a local area through adownlink. With respect to V2I, if a receiver is a BS-type roadside unit(RSU), a UE transmits a V2I message to an BS-type RSU through an uplink;and if a transmitter is a BS-type RSU, the BS-type RSU) transmits theV2I message to a plurality of UEs present in a local area. With respectto V2P, a transmitter UE or receiver UE(s) may be a pedestrian UE. Tosupport this scenario, the BS performs uplink reception and downlinktransmission of a V2X message and uses a broadcast mechanism withrespect to a downlink.

The following Table 4 and FIG. 3 may refer to a scenario for supportinga V2X operation that uses all of a UE interface and PC5 interface (orSL). Here, (a) of FIG. 3 illustrates Scenario 3A of Table 4 and (b) ofFIG. 3 illustrates Scenario 3B of Table 4.

TABLE 4 Scenario in which a UE transmits a V2X message to other UEsthrough a sidelink Scenario 3A In this scenario, a UE transmits a V2Xmessage to other UEs through a sidelink. One of a plurality of receiverUEs is a UE-type RSU and receives the V2X message through the sidelinkand transmits the V2X message to an BS through an uplink. The BSreceives the V2X message from the UE-type RSU and transmits the V2Xmessage to a plurality of UEs present in a local area through adownlink. To support this scenario, the BS performs uplink reception anddownlink transmission of the V2X message, and uses a broadcast mechanismwith respect to the downlink. Scenario 3B In this scenario, a UEtransmits a V2X message to an BS through an uplink. The BS transmits theV2X message to at least one UE-type RSU. The UE-type RSU transmits theV2X message to other UEs through a sidelink. To support this scenario,the BS performs uplink reception and downlink transmission of the V2Xmessage, and uses a broadcast mechanism with respect to the downlink.

As described above, the V2X communication may be performed through theBS and may be performed through direct communication between UEs. Here,if the BS is used, transmission and reception may be performed through aUu link that is a communication interface between an LTE BS and UE inLTE-based V2X communication. Also, if the sidelink is used for thedirect communication between UEs, transmission and reception may beperformed through a PC5 link that is a communication interface betweenLTE UEs in the LTE-based V2X communication.

In LTE, communication from a BS to a UE is referred to as a downlink(DL) and communication from the UE to the BS is referred to as an uplink(UL). Communication from a UE to another UE is further defined as asidelink (SL) in addition to the uplink (UL) and the downlink (DL).

In the LTE, a technical item of initially using and applying PC5 basedsidelink communication is D2D that is a proximity communication (ProSe)for public safety and commercial purposes. Also, in the LTE, a nexttechnical item of applying the PC5 based sidelink communication is V2Xthat is a communication for vehicles.

FIG. 4 illustrates an example of a service provided based on a sidelink.

Referring to FIG. 4 , a V2X related service or an Internet of Things(IoT) service may be provided based on a 5G sidelink. Here, for example,the 5G sidelink may be a concept that includes all of a sidelink basedon an existing LTE system and a sidelink based on an NR system. That is,the 5G sidelink may be a service that is provided by considering thesidelink applied in each system. However, it is provided as an exampleonly.

For example, referring to FIG. 4 , with respect to a V2X service, avehicle platooning, an automatic driving, an advanced sensor, and aremote driving service may be provided. Here, the vehicle platooning mayrefer to technology that allows a plurality of vehicles to dynamicallyform a group and operate in a similar manner. Also, the automaticdriving may refer to technology that drives a vehicle based on acomplete automation and a semi-automation. Also, the advanced sensor mayrefer to technology that collects and exchanges data acquired from asensor or a video image. Also, the remote driving may refer totechnology for remotely controlling a vehicle and technology for anapplication. That is, the aforementioned services may be provided as aV2X-based service. Here, the services are provided as examples only andthe present disclosure is not limited thereto. Here, requirements, suchas ultra latency, ultra connectivity, low power, and high reliability,may be required to provide the V2X service. Therefore, the 5G sidelinkmay require an operation method for meeting the services and therequirements according thereto. A detailed method considering therequirements is described in the following.

FIG. 5 illustrates an example of a downlink synchronization signal in awireless communication system.

In an NR system, two types of synchronization signals may be defined.For example, the two types of synchronization signals may include anNR-primary synchronization signal (NR-PSS) and an NR-secondarysynchronization signal (NR-SSS).

The NR-PSS may be used to perform synchronization on an initial symbolboundary in an NR cell.

The NR-SSS may be used to detect an NR cell identifier (ID).

In a previous wireless communication system (e.g., LTE/LTE-A system) ofthe NR system, a bandwidth for transmission of a PSS/SSS and/or PhysicalBroadcast Channel (PBCH) is defined as 1.08 megahertz (MHz)corresponding to six physical resource blocks (PRBs). The NR system mayuse a relatively wide transmission bandwidth to transmit an NR-PSS/SSSand/or NR-PBCH compared to the previous wireless communication system.To this end, the NR system may use a subcarrier spacing (SCS) greaterthan 15 kilohertz (kHz).

If operating in 6 gigahertz (GHz) or less, one of 15 kHz and 30 kHz maybe considered as a default SCS. If operating in 6 GHz or more (e.g., ifoperating between 6 GHz and 52.5 GHz), one of 120 kHz and 240 kHz may beconsidered as a default SCS.

In detail, a default SCS set and a minimum carrier bandwidth assumed bya UE during an initial access may be defined as follows. If operating in6 GHz or less, the UE may basically assume a 15 kHz SCS and a bandwidthof 5 MHz. Also, the UE may assume a 30 kHz SCS and a bandwidth of 10 MHzin a specific band. Also, if operating in 6 GHz or more, the UE mayassume a 120 kHz SCS and a bandwidth of 10 MHz.

Also, an SCS supported for data and/or control information based on aspecific frequency band may be defined as follows. If operating in 1 GHzor less, SCSs of 15 kHz, 30 kHz, and 60 kHz may be supported. Ifoperating between 1 GHz and 6 GHz, SCSs of 15 kHz, 30 kHz, and 60 kHzmay be supported. If operating between 24 GHz and 52.6 GHz, SCSs of 60kHz and 120 kHz may be supported and 240 kHz may not be supported fordata. An SCS to be supported may be defined based on a band.

The NR-PSS, the NR-SSS, and/or the NR-PBCH may be transmitted in asynchronization signal (SS) block. Here, the SS block refers to atime-frequency resource area including all of the NR-PSS, the NR-SSS,and/or the NR-PBCH.

At least one SS block may constitute an SS burst. A single SS burst maybe defined to include a predetermined number of SS blocks, which mayalso be referred to as a duration of the SS burst. Also, at least one SSblock may be continuous or discontinuous within a single SS burst. Also,at least one SS block within a single SS burst may be identical ordifferent.

At least one SS burst may constitute an SS burst set. A single SS burstset may be defined to include a predetermined periodicity and apredetermined number of SS bursts. A number of SS bursts within the SSburst set may be defined to be finite. Also, a transmission point intime of the SS burst set may be periodically defined and may also beaperiodically defined.

At least one SCS may be predefined for each synchronization signal(e.g., NR-PSS, NR-SSS, NR-PBCH) with respect to a specific frequencyrange or carrier. For example, at least one of 15, 30, 120, and 240 kHzmay be applied as an SCS.

Here, an SCS for the NR-PSS, the NR-SSS, or the NR-PBCH may beidentical. Also, at least one frequency range may be given, anddifferent frequency ranges may overlap. Also, a single numerology may bedefined and a plurality of numerologies may be defined with respect to aspecific frequency range. Accordingly, one or more SCSs may be definedwith respect to the specific frequency range.

Also, from a point of view of a UE, the SS burst set may be periodicallytransmitted.

FIG. 6 illustrates an example of a transmission through a plurality ofbeams in a synchronization signal transmission according to the presentdisclosure.

To overcome a poor channel environment, such as high pathloss,phase-noise, and frequency offset, occurring in a high carrierfrequency, an NR system may consider a transmission of a synchronizationsignal, a random access signal, and a broadcast channel through aplurality of beams.

With respect to the transmission through the plurality of beams, anumber of beams used for the transmission and a width of each beam maybe variously determined based on a cell environment. Accordingly, astandardization regarding a maximum number of beams and a maximum amountof physical resources required for the transmission is required toprovide a degree of freedom for implementation as above.

Hereinafter, a method of transmitting a beam in an SS burst including asingle SS block or a plurality of SS blocks is described with referenceto FIG. 6 .

Referring to (a) of FIG. 6 , a single beam is applied for each single SSblock and, in general, an analog beamforming method is applied. In thiscase, a number of applicable beams is limited based on a number of radiofrequency (RF) chains.

Referring to (b) of FIG. 6 , two beams are applied for each single SSblock and, in general, a digital beamforming method or a hybridbeamforming method is applied. Using this method, beam sweeping forcovering a target coverage area may be performed further quickly.Therefore, a relatively small number of SS blocks may be used comparedto that in (a) of FIG. 6 , which may lead to enhancing a networkresource consumption efficiency.

FIG. 7 illustrates an example of a structure of a synchronization signalframe in the case of considering a transmission through a plurality ofbeams in a synchronization signal transmission according to the presentdisclosure.

Referring to FIG. 7 , in an NR system, a transmission of at least onebeam may apply to the same SS block. When a plurality of beams istransmitted to a single SS block, an SS block transmission to whichdifferent beam patterns are applied through beam sweeping may beperformed to satisfy a target coverage area. Here, the target coveragearea indicates that transmission of at least one beam and transmissionof each beam are performed to cover the target coverage area based on abeam width/azimuth intended by a base station.

Referring to FIG. 7 , a synchronization signal may be transmitted byapplying a single beam or a plurality of beams for each single SS block.Within a single SS block, at least one of an NR-PSS, an NR-SSS, and anNR-PBCH may be transmitted. With respect to a given frequency band, asingle SS block corresponds to N OFDM symbols defined based on a defaultSCS. Here, N denotes a constant. For example, if N=4, four OFDM symbolsmay be used within a single SS block. Here, a single OFDM symbol may beused for the NR-PSS, another single OFDM symbol may be used for theNR-SSS, and the remaining two OFDM symbols may be used for the NR-PBCH.

Referring to FIG. 7 , a single SS block or a plurality of SS blocks maybe configured as a single SS burst. SS blocks that constitute a singleSS burst may be consecutively allocated or inconsecutively allocated ina time domain or a frequency domain.

Referring to FIG. 7 , a single SS burst or a plurality of SS bursts maybe configured as a single SS burst set. From a point of view of a UE,the SS burst set is periodically transmitted and the UE assumes adefault transmission period value during an initial cell selection perspecific carrier frequency. The UE may receive updated information onthe SS burst set transmission period from the base station.

The UE may induce a symbol/slot index and a radio frame index from asingle SS block time index. A symbol/slot index and a radio frame indexaccording to an SS block time index of each SS block may be prefixed andthereby defined. Accordingly, if the SS block time index of each SSblock is known, a frame/symbol timing of each SS block may be knownbased on a relationship between the SS block time index and thesymbol/slot index and the radio frame index that are prefixed andthereby defined. Through this, the entire frame/symbol timings may beknown.

Here, in the case of the SS block time index, 1) an SS burst index maybe defined within the SS burst set and a time index for a single SSblock may be defined for each SS block within a single SS burst, and 2)a time index for a single SS block may be defined for each SS blockwithin an SS burst set.

Also, transmission of SS blocks within the SS burst set may be confinedwithin a 5-ms window regardless of SS burst set periodicity. A number ofavailable candidate SS block locations within the 5-ms window may begiven as L. In detail, L denotes a maximum number of SS blocks withinthe SS burst set and may be defined based on a frequency range asfollows. For example, L=4 in the frequency range of 3 GHz or less, L=8in the frequency range of 3 GHz to 6 GHz, and L=64 in the frequencyrange of 6 GHz to 52.6 GHz.

Also, in the case of an initial access such as a cell selection, adefault value for the SS burst set periodicity may be defined as 20 ms.

FIG. 8 illustrates an example of a structure of a synchronization signal(SS) block according to the present disclosure.

Referring to FIG. 8 , an NR-PSS, an NR-SSS, and/or an NR-PBCH may bepresent in a single SS block. A single SS block may correspond to 4 OFDMsymbols in a time domain and may correspond to 20 PRBs in a frequencydomain. The NR-PSS may be mapped to 12 PRBs of a first symbol, theNR-SSS may be mapped to 12 PRBs of a third symbol, and the NR-PBCH maybe mapped to 20 PRBs of each of a second symbol and a fourth symbolwithin the SS block. Also, the NR-PBCH may be additionally mapped to 4PRBs at each of both ends of the third symbol of the SS block. Also, ademodulation-reference signal (DM-RS) associated with the NR-PBCH mayalso be mapped within the SS block.

Also, SCSs supported for the SS block may be 15 kHz and 30 kHz ifoperating in 6 GHz or less, and may be 120 kHz and 240 kHz if operatingin 6 GHz or more.

Hereinafter, a downlink synchronization signal sequence in an NR systemis described.

A total of 3 NR-PSS sequences may be present. If an NR-PSS is configuredbased on a pure binary phase shift keying (BPSK) M-sequence in afrequency domain, x⁷+x⁴+1 may be used as a primitive polynomial. A totalof 3 NR-PSS sequences may be acquired by cyclically shifting theprimitive polynomial by 0, 43, and 86 on the frequency domain. Here, ashift register value used to generate a sequence through the primitivepolynomial may be represented as 11101110 using a binary system. Here,the NR-PSS may have a sequence length of 127 and may be continuouslymapped to a total of 127 subcarriers.

Also, an NR-SSS may be configured based on a pure BPSK M-sequence. Here,the NR-SSS may have a sequence length of 127 identical to that of theNR-PSS, and may be continuously mapped to a total of 127 subcarriers.Here, since about 1000 physical cell IDs (PCIDs) are considered for NR,about 1000 NR-SSS sequences may be required.

M-sequence may be generated based on an irreducible primitive polynomialover GF(2). With respect to the length of 127(=2⁷−1), the M-sequence maybe generated based on one of a total of 18 irreducible primitivepolynomials as shown in the following Table 5.

TABLE 5 Decimal Octal Binary Polynomial 131 203 10000011 x⁷ + x + 1 137211 10001001 x⁷ + x³ + 1 143 217 10001111 x⁷ + x³ + x² + x + 1 145 22110010001 x⁷ + x⁴ + 1 157 235 10011101 x⁷ + x⁴ + x³ + x² + 1 167 24710100111 x⁷ + x⁵ + x² + x + 1 171 253 10101011 x⁷ + x⁵ + x³ + x + 1 185271 10111001 x⁷ + x⁵ + x⁴ + x³ + 1 191 277 10111111 x⁷ + x⁵ + x⁴ + x³ +x² + x + 1 193 301 11000001 x⁷ + x⁶ + 1 203 313 11001011 x⁷ + x⁶ + x³ +x + 1 211 323 11010011 x⁷ + x⁶ + x⁴ + x + 1 213 325 11010101 x⁷ + x⁶ +x⁴ + x² + 1 229 345 11100101 x⁷ + x⁶ + x⁵ + x² + 1 239 357 11101111 x⁷ +x⁶ + x⁵ + x³ + x² + x + 1 241 361 11110001 x⁷ + x⁶ + x⁵ + x⁴ + 1 247 36711110111 x⁷ + x⁶ + x⁵ + x⁴ + x² + x + 1 253 375 11111101 x⁷ + x⁶ + x⁵ +x⁴ + x³ + x² + 1

For example, referring to Table 5, in the case of using the primitivepolynomial x⁷+x³+1 (represented as 131 using a decimal system,represented as 211 using an octal system, and represented as 10001001using a binary system), the M-sequence may be generated according to thefollowing Equation 1. In Equation 1, x(i) denotes the M-sequence and0≤i≤126. Also, in Equation 1, x(ī+7) corresponds to x⁷ in the primitivepolynomial, x(ī+3) corresponds to x³ in the primitive polynomial, andx(ī) corresponds to 1 in the primitive polynomial. Althoughinitialization values x(0), x(1), x(2), x(3), x(4), x(5), and x(6) areexpressed as 0, 0, 0, 0, 0, 0, and 1, respectively, in Equation 1, theyare provided as an example only. That is, other initialization valuesmay be used.

x({dot over (i)}+7)=(x({dot over (i)}+7)+x({dot over (i)}+7)+x({dot over(i)}))mod2,0≤{dot over (i)}≤126,

x(0)=0,x(1)=0,x(2)=0,x(3)=0,x(4)=0,x(5)=0,x(6)=1  [Equation 1]

If the generated M-sequence is represented using BPSK, the M-sequencemay be modulated as represented by the following Equation 2. If asequence value of the M-sequence=0, the value becomes 1 in response toBPSK modulation. If a sequence value of the M-sequence=1, the valuebecomes −1 in response to BPSK modulation.

{tilde over (s)}(i)=1−2x(i),0≤i≤126  [Equation 2]

Finally, as represented by the following Equation 3, a total of 127sequences are generated by cyclically shifting the sequence {tilde over(s)}(i) of Equation 2 by m since a total of 127 values from 0 to 126 areavailable for a value of m. Therefore, {tilde over (s)}(i) correspondsto an NR-SSS sequence that is mapped to each of consecutive 127subcarriers on a frequency axis with respect to a single symbol within asubstantially single SS block.

s ^(m)(n)={tilde over (s)}((n+m)mod127),0≤i≤126  [Equation 3]

A correlation value of the BPSK M-sequence generated in theaforementioned manner is represented as the following Equation 4. InEquation 4, if following examples of Equation 1 to Equation 3, N=127corresponding to the length of the M-sequence. That is, as shown inEquation 4, a correlation value between sequences having the same cyclicshift (i.e., a correlation value with a corresponding sequence itself)is N, and otherwise, −1. That is, since the difference is great, theBPSK M-sequence may have a very excellent correlation characteristic.

$\begin{matrix}{{R_{s}(\tau)} = {{\sum\limits_{n = 0}^{N - 1}{{s^{m}(n)} \cdot {s^{m + \tau}(n)}}} = \left\{ \begin{matrix}{N,} & {\tau = 0} \\{{- 1},} & {\tau \neq 0}\end{matrix}\  \right.}} & \left\lbrack {{Equation}4} \right\rbrack\end{matrix}$

As described above, the BPSK M-sequence has an excellent correlationcharacteristic. However, considering a sequence with a length of 127 formapping to a total of 127 subcarriers on a frequency, a total number ofsequences is 127 and thus, limited. As described above, about 1000 NRPCIDs need to be classified. Here, although scrambling is applied basedon three NR-PSSs with respect to each of the 127 NR-SSS sequences, atotal of 127.3=381 different sequence combinations are present and about1000 NR PCIDs may not be classified accordingly. Therefore, a method ofgenerating a greater number of sequences is required.

To generate a greater number of sequences, a plurality of irreducibleprimitive polynomials may be used instead of using a single irreducibleprimitive polynomial as described above with reference to Equation 1 toEquation 3. To generate the M-sequence with the length of 127 as shownin Table 5, one of a total of 18 irreducible primitive polynomials maybe used. Therefore, a maximum of K primitive polynomials may be usedamong a total of 18 primitive polynomials as follows.

If x₀(i) refers to an M-sequence generated through a first primitivepolynomial, x₁(i) refers to an M-sequence generated through a secondprimitive polynomial, and, in this manner, x_(k)(i) refers to anM-sequence generated through a (k+1)-th primitive polynomial, a total of127K sequences may be generated. Here, 0≤k≤K−1 and a maximum value of Kis 18. Here, the (k+1)-th primitive polynomial may be one of 18primitive polynomials of Table 5. Also, a method of generating anM-sequence x_(k)(i) through each corresponding primitive polynomial mayfollow the method described above with reference to Equation 1.

If the generated M-sequence is represented using BPSK, modulation may beperformed as represented by the following Equation 5. If a sequencevalue of the M-sequence=0, the value becomes 1 in response to BPSKmodulation. If the sequence value of the M-sequence=1, the value becomes−1 in response to BPSK modulation.

{tilde over (s)} _(k)(i)=1−2x _(k)(i),0≤i≤126  [Equation 5]

As represented by Equation 6, a total of 127 sequences are generated bycyclically shifting the sequence {tilde over (s)}_(k)(i) of Equation 5by m since a total of 127 values from 0 to 126 are available for a valueof m. Also, 127 sequences may be generated with respect to each k and atotal of 127*K sequences may be finally generated. Here, 0≤k≤K−1 and amaximum value of K is 18. Therefore, s^(m)(n) corresponds to an NR-SSSsequence that is mapped to each of consecutive 127 subcarriers on afrequency axis with respect to a single symbol within a substantiallysingle SS block.

s _(k) ^(m)(n)={tilde over (s)} _(k)((n+m)mod127),0≤i≤126  [Equation 6]

A correlation value of the BPSK M-sequence generated in theaforementioned manner is represented as the following Equation 7. Here,a maximum absolute value (here, the maximum absolute value referring toa maximum absolute value among values excluding a correlation value witha corresponding sequence itself) of a correlation value according toEquation 7 is 41 of which a difference with 127 is not great compared toEquation 4 of which a corresponding value is 1 (1 if an absolute valueis applied to −1). Therefore, a maximum of 127*K sequences may begenerated, which may be sufficient to classify about 1000 NR PCIDs.However, a correlation characteristic may be poor.

$\begin{matrix}{{R_{s_{k},s_{k^{\prime}}}(\tau)} = {\sum\limits_{n = 0}^{N - 1}{{s_{k}^{m}(n)} \cdot {s_{k^{\prime}}^{m + \tau}(n)}}}} & \left\lbrack {{Equation}7} \right\rbrack\end{matrix}$

Here, in the case of generating an M-sequence based on a maximumconnected set of the M-sequence instead of generating the M-sequencefrom each of a total of K primitive polynomials, sequences having afurther excellent correlation characteristic may be generated. Themaximum connected set of the M-sequence may have a total of 18 sets asshown in Table 6 with respect to the M-sequence with the length of 127.The primitive polynomials of Table 5 may be represented using an octalsystem as primitive polynomials of the following Table 6.

TABLE 6 Polynomial 1 Polynomial 2 Polynomial 3 Polynomial 4 Polynomial 5Polynomial 6 set 1 211 217 277 323 203 253 set 2 217 277 323 203 253 271set 3 277 323 203 253 271 367 set 4 323 203 253 271 367 345 set 5 203253 271 367 345 221 set 6 253 271 367 345 221 361 set 7 271 367 345 221361 375 set 8 367 345 221 361 375 313 set 9 345 221 361 375 313 301 set10 221 361 375 313 301 325 set 11 361 375 313 301 325 235 set 12 375 313301 325 235 357 set 13 313 301 325 235 357 247 set 14 301 325 235 357247 211 set 15 325 235 357 247 211 217 set 16 235 357 247 211 217 277set 17 357 247 211 217 277 323 set 18 247 211 217 277 323 203

If x₀(i) refers to an M-sequence generated through a first primitivepolynomial, x₁(i) refers to an M-sequence generated through a secondprimitive polynomial, and, in this manner, x_(k)(i) refers to anM-sequence generated through a (k+1)-th primitive polynomial (here,0≤k≤K−1), a maximum value of K is 6, which differs from the methoddescribed above with reference to Equation 5 and Equation 6. Here, therespective primitive polynomials need to be primitive polynomialsbelonging to the maximum connected set of the above Table 6.

For example, in the case of using a maximum connected set 1 of Table 6,a primitive polynomial needs to be represented as one of 211, 217, 277,323, 203, and 253 in response to a representation using an octal system.

Hereinafter, a PCID and a synchronization signal in an NR system will bedescribed. In the NR system, the range of a PCID is from 0 to 1007 andmay have one of 1008 distinguishable values. The PCID may be representedas N_(ID) ^(cell) and may be defined as N_(ID) ^(cell)=3N_(ID)⁽¹⁾+N_(ID) ⁽²⁾.

Here, N_(ID) ⁽¹⁾ may have a single value of {0, 1, . . . , 335} andN_(ID) ⁽²⁾ may have a single value of {0, 1, 2}. That is, N_(ID) ⁽¹⁾ mayhave a single value among 336 hypothesis values and N_(ID) ⁽²⁾ may havea single value among three hypothesis values.

N_(ID) ⁽¹⁾ may be given by an NR-SSS and N_(ID) ⁽²⁾ may be given by anNR-PSS. That is, a base station that transmits a synchronization signalmay determine values of N_(ID) ⁽¹⁾ and N_(ID) ⁽²⁾ corresponding to aPCID value N_(ID) ^(cell) of the base station and may generate andtransmit NR-SSS and NR-PSS sequences based on the respective determinedvalues of N_(ID) ⁽¹⁾ and N_(ID) ⁽²⁾. A UE that receives asynchronization signal for an initial cell selection may verify NIDI)and N_(ID) ⁽²⁾ from the detected NR-SSS sequence and NR-PSS sequence,respectively, and may determine a PCID of a corresponding cell based onN_(ID) ^(cell)=3N_(ID) ⁽¹⁾+N_(ID) ⁽²⁾.

Hereinafter, a process of generating NR-PSS and NR-SSS sequences isdescribed.

Generation of a sequence d_(PSS)(n) for an NR-PSS using an M-sequencemay be represented as the following Equation 8.

d _(PSS)(n)=1−2x(m)

m=(n+43N _(ID) ⁽²⁾)mod127

0≤n<127

where

x(i+7)=(x(i+4)+x(i))mod2

and

[x(6)x(5)x(4)x(3)x(2)x(1)x(0)]=[1 1 1 0 1 1 0]  [Equation 8]

Referring to Equation 8, the NR-PSS may be generated using a frequencydomain-based pure BPSK M-sequence. Also, three NR-PSSs may be acquiredby applying three cyclic shift (CS) values in the frequency domain. Thatis, the CS value may be defined as CS=0 if N_(ID) ⁽²⁾=0, CS=43 if N_(ID)⁽²⁾=1, and CS=86 if N_(ID) ⁽²⁾=2. Also, the NR-PSS sequence may have alength of 127 in the case of the frequency domain-based pure BPSKM-sequence.

Generation of a sequence d_(PSS)(n) for an NR-SSS using an M-sequencemay be represented as the following Equation 9.

d _(SSS)(n)=[1−2x ₀((n+m ₀)mod127)][1−2x ₁((n+m ₁)mod127)]

m ₀=15└N _(ID) ⁽¹⁾/112┘+5N _(ID) ⁽²⁾

m ₁ =N _(ID) ⁽¹⁾mod112

0≤n<127

where

x ₀(i+7)=(x ₀(i+4)+x ₀(i))mod2

x ₁(i+7)=(x ₁(i+1)+x ₁(i))mod2

and

[x ₀(6)x ₀(5)x ₀(4)x ₀(3)x ₀(2)x ₀(1)x ₀(0)]=[0 0 0 0 0 0 1]

[x ₁(6)x ₁(5)x ₁(4)x ₁(3)x ₁(2)x ₁(1)x ₁(0)]=[0 0 0 0 0 0 1]  [Equation9]

Referring to Equation 9, the NR-SSS sequence may be generated using asingle polynomial to which 112 cyclic shifts are applied and anadditional single polynomial to which 9 cyclic shifts are applied.

Here, cyclic shift values m₀ and m₁ may be determined based on a cell ID(i.e., N_(id) ^(cell)=3N_(ID) ⁽¹⁾+N_(ID) ⁽²⁾) extracted from the NR-PSS(i.e., N_(ID) ⁽²⁾=0, 1, 2) and the NR-SSS (i.e., N_(ID) ⁽¹⁾=0, 1, . . ., 335). For example, m₀ may have a single value among 9 cases including0, 5, 10, 15, 20, 25, 30, 35, and 40, and m₁ may have a single valueamong 112 cases including 0 to 111. Accordingly, available combinationsof m₀ and m₁ may correspond to a total of 1008 (=9*112) cell IDs (i.e.,PCID).

The generated NR-PSS and NR-SSS sequences may be mapped ontime-frequency resources of an SS block. The NR-PSS may be mapped onconsecutive 127 subcarriers present in the middle of a frequency domainat a time location of a single specific symbol of the SS block, and theNR-SSS may be mapped on consecutive 127 subcarriers present in themiddle of the frequency domain at a time location of another specificsymbol of the SS block. In the example of FIG. 8 , the NR-PSS sequenceor the NR-SSS sequence is described to be mapped on 12 PRBs (=12*12=144subcarriers). In detail, the NR-PSS sequence or the NR-SSS sequence ismapped on 127 subcarriers present in the middle of 144 subcarriers of 12PRBs and the NR-PSS sequence or the NR-SSS sequence may not be mapped to8 subcarriers corresponding to a low frequency and 9 subcarrierscorresponding to a high frequency.

Hereinafter, a method and apparatus for setting and generating asidelink synchronization signal sequence in a wireless communicationsystem and a method and apparatus for transmitting and receiving asidelink synchronization signal according to the present disclosure willbe described.

FIG. 9 illustrates an example of a sidelink synchronization referenceaccording to the present disclosure.

Referring to FIG. 9 , it is assumed that, in a wireless communicationsystem, a first UE (UE1) 910 is present in network coverage 905 of abase station 900, and a second UE (UE2) 920, a third UE (UE3) 930, afourth UE (UE4) 940, and a fifth UE (UE5) 950 are present out of thenetwork coverage 905.

Here, the wireless communication system may be a 5G network thatsupports LTE based technology (i.e., LTE and LTE enhanced radio accesstechnology) as well as NR. Also, the base station 900 may be gNB or eNB.As described above, the wireless communication system of FIG. 9 mayapply to all of a case in which an NR system independently operates andthe NR system and an LTE based system operate together. Also, sidelinktechnology of the wireless communication system may include all of NRsidelink technology and LTE based sidelink technology.

Herein, a sidelink synchronization reference may be classified into aplurality of types. Also, a physical layer sidelink synchronizationidentity set for a corresponding sidelink synchronization signal may bedistinguishably defined based on a type into which the sidelinksynchronization reference is classified.

As a first example, a synchronization reference may be classified intotwo types based on whether a source of synchronization is an entitypresent in the network coverage 905 (i.e., an in-coverage entity) or anentity located out of the network coverage 905 (i.e., an out-of-coverageentity).

In detail, since the UE2 920 performs synchronization using asynchronization signal from the UE1 910 and the UE1 910 performssynchronization using a synchronization signal from the base station900, the UE2 920 uses the in-coverage entity as a source ofsynchronization. The UE3 930 performs synchronization using asynchronization signal from the UE2 920, the UE2 920 performssynchronization using a synchronization signal from the UE1 910, and theUE1 910 performs synchronization using a synchronization signal from thebase station 900. Accordingly, the UE3 930 uses the in-coverage entityas a source of synchronization. In this case, a synchronizationreference of a sidelink 915 between the UE1 910 and the UE2 920 or asynchronization reference of a sidelink 925 between the UE2 920 and theUE3 930 may be referred to as a first type synchronization reference.

The UE5 950 present out of the coverage performs synchronization using asynchronization signal from the UE4 940 present out of the coverage. Inthis case, a synchronization reference of a sidelink 945 between the UE4940 and the UE5 950 may be referred to as a second type synchronizationreference.

A sidelink synchronization identity set corresponding to the first typesynchronization reference may be referred to as id_net, and a sidelinksynchronization identity set corresponding to the second typesynchronization reference may be referred to as id_oon. That is, id_netmay apply to the first sidelink 915 and the second sidelink 925 andid_oon may apply to the third sidelink 945.

As a second example, a synchronization reference may be classified intothree types based on whether a source of synchronization is anin-coverage entity or an out-of-coverage entity, whether thesynchronization signal is transmitted from the in-coverage entity to theout-of-coverage entity, or whether the synchronization signal istransmitted from the out-of-coverage entity to another out-of-coverageentity.

In detail, since the UE2 920 performs synchronization using asynchronization signal from the UE1 910 and the UE1 910 performssynchronization using a synchronization signal from the base station,the UE2 920 uses the in-coverage entity as a source of synchronization.Also, the UE1 910 is present in the coverage and the UE2 920 is presentout of the coverage. In this case, a synchronization reference of thesidelink 915 between the UE1 910 and the UE2 920 may be referred to as afirst type synchronization reference.

The UE3 930 performs synchronization using a synchronization signal fromthe UE2 920, the UE2 920 performs synchronization using asynchronization signal from the UE1 910, and the UE1 910 performssynchronization using a synchronization signal from the base station900. Therefore, the UE3 930 uses the in-coverage entity as a source ofsynchronization. Also, all of the UE2 920 and the UE3 930 are presentout of the coverage. In this case, a synchronization reference of thesidelink 925 between the UE2 920 and the UE3 930 may be referred to as asecond type synchronization reference.

The UE5 950 present out of the coverage performs synchronization using asynchronization signal from the UE4 940 present out of the coverage. Inthis case, a synchronization reference of the sidelink 945 between theUE4 940 and the UE5 950 may be referred to as a third typesynchronization reference.

A sidelink synchronization identity set corresponding to the first typesynchronization reference may be referred to as id_net_1, a sidelinksynchronization identity set corresponding to the second typesynchronization reference may be referred to as id_net_2, and a sidelinksynchronization identity set corresponding to the third typesynchronization reference may be referred to as id_oon. That is,id_net_1 may apply to the first sidelink 915, id_net_2 may apply to thesecond sidelink 925, and id_oon may apply to the third sidelink 945.

As a third example, a synchronization reference may be classified intothree types based on whether a source of synchronization is anin-coverage entity or an out-of-coverage entity and based on a type ofradio access technology followed by the source of synchronization.

In detail, if a source of synchronization of the UE2 920 or the UE3 930is an entity (e.g., gNB of an NR system) present in the coverage andaccording to a first type of radio access technology, a correspondingsynchronization reference may be referred to as a first typesynchronization reference. For example, if the base station 900 of FIG.9 is gNB, a synchronization reference of the sidelink 915 between theUE1 910 and the UE2 920 or the sidelink 925 between the UE2 920 and theUE3 930 may be referred as a first type synchronization reference.

Alternatively, if a source of synchronization of the UE2 920 or the UE3930 is an entity (e.g., eNB of an LTE based system) present in thecoverage and according to a second type of radio access technology, acorresponding synchronization reference may be referred to as a secondtype synchronization reference. For example, if the base station 900 ofFIG. 9 is eNB, a synchronization reference of the sidelink 915 betweenthe UE1 910 and the UE2 920 or the sidelink 925 between the UE2 920 andthe UE3 930 may be referred to as a second type synchronizationreference.

The UE5 950 present out of the coverage performs synchronization using asynchronization signal from the UE4 940 present out of the coverage. Inthis case, a synchronization reference of the sidelink 945 between theUE4 940 and the UE5 950 may be referred to as a third typesynchronization reference.

A sidelink synchronization identity set corresponding to the first typesynchronization reference may be referred to as id_net_1, a sidelinksynchronization identity set corresponding to the second typesynchronization reference may be referred to as id_net_2, and a sidelinksynchronization identity set corresponding to the third typesynchronization reference may be referred to as id_oon. That is,id_net_1 may apply to the first sidelink 915, id_net_2 may apply to thesecond sidelink 925, and id_oon may apply to the third sidelink 945.

According to the present disclosure, two or three types may be definedfor a type of a synchronization reference or a type of a physical layersidelink synchronization identity set.

If the synchronization identity set is defined using two types, id_netthat uses an in-coverage entity as a synchronization reference andid_oon that uses an out-of-coverage entity as a synchronizationreference may be defined.

If the synchronization identity set is defined using three types,id_net_1 for a case in which an in-coverage entity is used for asynchronization reference and a sidelink synchronization signal istransmitted from the in-coverage entity to an out-of-coverage entity,id_net_2 for a case in which an in-coverage entity is used for asynchronization reference and a sidelink synchronization signal istransmitted from an out-of-coverage entity to another out-of-coverageentity, and id_oon that uses an out-of-coverage entity for asynchronization reference may be defined.

Alternatively, if the synchronization identity set is defined usingthree types, id_net_1 that uses, for a synchronization reference, anin-coverage entity according to a first type of radio access technology,id_net_2 that uses, for a synchronization reference, an in-coverageentity according to a second type of radio access technology, and id_oonthat uses an out-of-coverage entity for a synchronization reference maybe defined.

FIG. 10 is a flowchart illustrating an example of a method oftransmitting a sidelink synchronization signal sequence according to thepresent disclosure.

The sidelink synchronization signal transmitting method of FIG. 10 maybe performed by a sidelink transmitting UE (hereinafter, a transmittingUE).

Referring to FIG. 10 , in operation S1010, the transmitting UE maydetermine values of N_(ID) ⁽¹⁾ and N_(ID) ⁽²⁾ based on sidelink identity(SLID) or N_(ID) ^(SL) corresponding to physical layer sidelinksynchronization identity information.

Here, various examples of the present disclosure may include a case inwhich a physical layer sidelink synchronization identity set isconfigured using two types (e.g., id_net and id_oon in the example ofFIG. 9 ) or a case in which the physical layer sidelink synchronizationidentity set is configured using three types (e.g., id_net_1, id_net_2,and id_oon in the example of FIG. 9 ).

Also, various examples of the present disclosure may include a case inwhich each type of the physical layer sidelink synchronization identityset (e.g., each of id_net and id_oon, or each of id_net_1, id_net_2, andid_oon in the example of FIG. 9 ) includes 168 sequences, a case inwhich each type thereof includes 336 sequences, a case in which eachtype thereof includes 504 sequences, or a case in which each typethereof includes 1008 sequences.

As described above, values of N_(ID) ⁽¹⁾ and N_(ID) ⁽²⁾ corresponding toan SLID value may be determined based on a number of types of a physicallayer sidelink synchronization identity sets and a number ofsynchronization signal sequences included in each type of the identityset.

In operation S1020, the transmitting UE may generate an NR-primarysidelink synchronization signal (PSSS) sequence by applying a firstinitialization value to a first primitive polynomial. Also, thetransmitting UE may determine a cyclic shift (CS) value to be applied tothe generated NR-PSSS sequence based on the value of N_(ID) ⁽²⁾ and mayapply CS to the NR-PSSS sequence.

Here, in various examples of the present disclosure, an NR sidelinksynchronization signal sequence may be distinguished from an NR downlinksynchronization signal sequence by applying a first primitive polynomialused to generate an NR-PSSS sequence to be distinguished from a firstprimitive polynomial applied to the NR downlink synchronization signalsequence.

Also, in various examples of the present disclosure, an NR sidelinksynchronization signal sequence may be distinguished from an NR downlinksynchronization signal sequence by applying a CA value for an NR-PSSSdistinguished from a CS value applied to the NR downlink synchronizationsignal sequence.

In operation S1030, the transmitting UE may generate a firstNR-secondary sidelink synchronization signal (NR-SSSS) sequence byapplying a second initialization value to the first primitive polynomialand may generate a second NR-SSSS sequence by applying the secondinitialization value to the second primitive polynomial.

Here, in various examples of the present disclosure, an NR sidelinksynchronization signal sequence may be distinguished from an NR downlinksynchronization signal sequence by applying at least one of first andsecond primitive polynomials used to generate an NR-SSSS sequence to bedistinguished from at least one of first and second primitivepolynomials applied to the NR downlink synchronization signal sequence.

In operation S1040, the transmitting UE may determine a CS value to beapplied to the generated first NR-SSSS sequence based on the values ofN_(ID) ⁽¹⁾ and N_(ID) ⁽²⁾ and may apply CS to the first NR-SSSSsequence. Also, the transmitting UE may determine a CS value to beapplied to the generated second NR-SSSS sequence based on the values ofN_(ID) ⁽¹⁾ and N_(ID) ⁽²⁾ and may apply CS to the second NR-SSSSsequence.

Here, in various examples of the present disclosure, an NR sidelinksynchronization signal sequence may be distinguished from an NR downlinksynchronization signal sequence by applying at least one of a CS valuefor a first NR-SSSS sequence and a CS value for a second NR-SSSSsequence to be distinguished from a CS value applied to the NR downlinksynchronization signal sequence.

In operation S1050, the transmitting UE may generate an NR-PSSSmodulation symbol by performing BPSK modulation of the NR-PSSS sequenceto which the CS is applied. Also, the transmitting UE may generate anNR-SSSS modulation symbol by multiplying a BPSK modulation result of thefirst NR-SSSS sequence to which the CS is applied by a BPSK modulationresult of the second NR-SSSS sequence to which the CS is applied.

In operation S1060, the transmitting UE may map the NR-PSSS modulationsymbol on consecutive subcarriers on a frequency in a single symbolwithin a single SS block and may map the NR-SSSS modulation symbol onconsecutive subcarriers on the frequency in another symbol within thesingle SS block. The transmitting UE may generate and transmit asynchronization signal based on a modulation symbol mapped ontime-frequency resources.

FIG. 11 is a flowchart illustrating an example of a method of receivinga sidelink synchronization signal sequence according to the presentdisclosure.

The sidelink synchronization signal receiving method of FIG. 11 may beperformed by a sidelink receiving UE (hereinafter, a receiving UE).

Referring to FIG. 11 , in operation S1110, the receiving UE may receivea synchronization signal from a transmitting UE. The receiving UE maydetect, from the synchronization signal, an NR-PSSS modulation symbolmapped on consecutive subcarriers on a frequency in a single symbolwithin a single SS block, and may detect an NR-SSSS modulation symbolmapped on consecutive subcarriers on the frequency in another symbolwithin the single SS block.

In operation S1120, the receiving UE may determine an NR-PSSS sequenceto which CS is applied from the detected NR-PSSS modulation symbol.Also, the receiving UE may determine a first NR-SSSS sequence to whichthe CS is applied and a second NR-SSSS sequence to which the CS isapplied from the detected NR-SSSS modulation symbol.

In operation S1130, the receiving UE may calculate a value of N_(ID) ⁽²⁾based on a first primitive polynomial and a CS value applied to thedetermined NR-PSSS sequence.

Here, in various examples of the present disclosure, an NR sidelinksynchronization signal sequence may be distinguished from an NR downlinksynchronization signal sequence by applying a first primitive polynomialused to generate an NR-PSSS sequence to be distinguished from a firstprimitive polynomial applied to the NR downlink synchronization signalsequence.

Also, in various examples of the present disclosure, an NR sidelinksynchronization signal sequence may be distinguished from an NR downlinksynchronization signal sequence by applying a CS value for an NR-PSSSsequence to be distinguished from a CS value applied to the NR downlinksynchronization signal sequence.

The receiving UE may be pre-aware of a first primitive polynomial and acandidate CS value applicable to generate the NR-PSSS sequence.Therefore, the receiving UE may verify a CS value applied to acorresponding NR-PSSS sequence from the NR-PSSS sequence determined inoperation S1120 and may calculate a value of N_(ID) ⁽²⁾ value from theverified CS value.

In operation S1140, the receiving UE may calculate a value of N_(ID) ⁽¹⁾based on the CS value applied to the determined first NR-SSSS sequenceand the CS value applied to the second NR-SSSS sequence.

Here, in various examples of the present disclosure, an NR sidelinksynchronization signal sequence may be distinguished from an NR downlinksynchronization signal sequence by applying at least one of first andsecond primitive polynomials used to generate an NR-SSSS sequence to bedistinguished from at least one of first and second primitivepolynomials applied to the NR downlink synchronization signal sequence.

Also, in various examples of the present disclosure, an NR sidelinksynchronization signal sequence may be distinguished from an NR downlinksynchronization signal sequence by applying at least one of a CS valuefor a first NR-SSSS sequence and a CS value for a second NR-SSSSsequence to be distinguished from a CS value applied to the NR downlinksynchronization signal sequence.

The receiving UE may be pre-aware of first and second primitivepolynomials and a candidate CS value applicable to generate the firstand second NR-SSSS sequences. Therefore, the receiving UE may verify aCS value applied to each NR-PSSS sequence from each of the first andsecond NR-SSSS sequences determined in operation S1120, and maycalculate the value of N_(ID) ⁽¹⁾ from the verified CS value and thevalue of N_(ID) ⁽²⁾ calculated in operation S1130.

In operation S1150, the receiving UE may determine an SLID (or N_(ID)^(SL)) value from the calculated values of NIDI) and N_(ID) ⁽²⁾.

Here, various examples of the present disclosure may include a case inwhich a physical layer sidelink synchronization identity set isconfigured using two types (e.g., id_net and id_oon in the example ofFIG. 9 ) or a case in which the physical layer sidelink synchronizationidentity set is configured using three types (e.g., id_net_1, id_net_2,and id_oon in the example of FIG. 9 ).

Also, various examples of the present disclosure may include a case inwhich each type of the physical layer sidelink synchronization identityset (e.g., each of id_net and id_oon, or each of id_net_1, id_net_2, andid_oon in the example of FIG. 9 ) includes 168 sequences, a case inwhich each type thereof includes 336 sequences, a case in which eachtype thereof includes 504 sequences, or a case in which each typethereof includes 1008 sequences.

The receiving UE may be pre-aware of a number of types of a physicallayer sidelink synchronization identity set and a number ofsynchronization signal sequences included in each type of the identityset and thus, may determine an SLID value corresponding to the values ofN_(ID) ⁽¹⁾ and N_(ID) ⁽²⁾.

Hereinafter, various examples of the present disclosure will be furtherdescribed. The examples of the present disclosure may include variouscombinations of an example about a number of types of a physical layersidelink synchronization identity set (i.e., example A series), anexample about a number of sequences included in each type of a physicallayer sidelink synchronization identity set (i.e., example B series), anexample about a type of an NR sidelink synchronization signal sequenceresource used to distinguish an NR sidelink synchronization signalsequence from an NR downlink synchronization signal sequence (i.e.,example C series).

Example A series may include a case (example A1) in which a physicallayer sidelink synchronization identity set is configured using twotypes and a case (example A2) in which a physical layer sidelinksynchronization identity set is configured using three types.

Example B series may include a case (example B1) in which each type of aphysical layer sidelink synchronization identity set includes 168sequences, a case (example B2) in which each type thereof includes 336(=168*2) sequences, a case (example B3) in which each type thereofincludes 504 sequences, and a case (example B4) in which each typethereof includes 1008 (=504*2) sequences.

Example C series may include a case (example C1) in which a type of anNR sidelink synchronization signal sequence resource used to distinguishan NR sidelink synchronization signal sequence from an NR downlinksynchronization signal sequence is a CS value applied to an NR-PSSS, acase (example C2) in which a type thereof is a CS value applied to anNR-SSSS, a case (example C3) in which a type thereof is a primitivepolynomial included in an NR-PSSS, and a case (example C4) in which atype thereof is a primitive polynomial applied to an NR-SSSS.

Further, example C series may further include an example correspondingto a combination of at least two of C1 to C4.

For example, a CS value applied to an NR-PSSS may be defined to bedistinguished from a CS value applied to an NR downlink PSS, and a CSvalue applied to an NR-SSSS may be defined to be distinguished from a CSvalue applied to an NR downlink SSS.

Alternatively, a primitive polynomial applied to an NR-PSSS may bedefined to be distinguished from a primitive polynomial applied to an NRdownlink PSS, and a primitive polynomial applied to an NR-SSSS may bedefined to be distinguished from a primitive polynomial applied to an NRdownlink SSS.

Alternatively, a primitive polynomial applied to the NR-PSSS may bedefined to be distinguished from a primitive polynomial applied to theNR downlink PSS, and a CS value applied to an NR-SSSS may be defined tobe distinguished from a CS value applied to an NR downlink SSS.

Alternatively, a CS value applied to an NR-PSSS may be defined to bedistinguished from a CS value applied to an NR downlink PSS, and aprimitive polynomial applied to an NR-SSSS may be defined to bedistinguished from a primitive polynomial applied to an NR downlink SSS.

Alternatively, a primitive polynomial and a CS value applied to anNR-PSSS and a primitive polynomial and a CS value applied to an NR-SSSSmay be defined to be distinguished from a primitive polynomial and a CSvalue applied to an NR downlink PSS and a primitive polynomial and a CSvalue applied to an NR downlink SSS.

As described above, various examples of the present disclosure mayinclude any possible combination of one of example A series, one ofexample B series, and one of example C series. For example, when an NRsidelink synchronization signal is defined to be generated based on arule corresponding to a single combination, the transmitting UE maygenerate and transmit NR-PSSS and NR-SSSS sequences corresponding to anSLID according to the rule, and the receiving UE may determine the SLIDby processing the received NR-PSSS and NR-SSSS sequences.

Hereinafter, examples of combinations of example A series, example Bseries, and example C series will be further described.

Examples A1 and B1

A physical layer sidelink synchronization identity set may be definedinto two types, that is, id_net and id_oon, and each of id_net andid_oon may include 168 sequences and may be defined as follows:

id_net={0,1, . . . ,167}

id_oon={168,169, . . . ,335}

N _(ID) ^(SL)={0,1, . . . ,335}

N _(ID) ⁽¹⁾ =N _(ID) ^(SL)mod168

N _(ID) ⁽²⁾=int(N _(ID) ^(SL)/168),N _(ID) ⁽²⁾={0,1}

Examples A1, B1, and C1

Sidelink PSS Resource (Example C1-PSS)

A primitive polynomial and an initialization value for a sidelink PSSmay be applied to be identical to those for a downlink PSS. Here, a CSvalue for the sidelink PSS may be applied to be different from a CSvalue for the downlink PSS.

For example, although the same primitive polynomial and initializationvalue as Equation 8 apply to the sidelink PSS, the CS value for thesidelink PSS may be defined as CS=0+k if N_(ID) ⁽²⁾=0 and CS=43+k ifN_(ID) ⁽²⁾=1 as represented by the following Equation 10. Here, althougha value of k=21 or 22 may be given, it is provided as an example only.

d _(PSS)(n)=1−2x(m)

m=(n+43N _(ID) ⁽²⁾ +k)mod127

0≤n<127  [Equation 10]

Accordingly, a value distinguished from the CS value applied to thedownlink PSS and corresponding to a farthest distance (e.g., as far ask) may be applied as the CS value applied to the sidelink PSS.

Sidelink SSS Resource (Example C1-SSS)

A primitive polynomial and an initialization value for a sidelink SSSmay be applied to be identical to those for a downlink SSS. Here, a CSvalue for the sidelink SSS may use a portion of CS values for thedownlink SSS.

That is, the primitive polynomial of Equation 9 may apply to thesidelink SSS and a portion of m₀={0, 5, 10, 15, 20, 25, 30, 35, 40} andm₁={0, 1, . . . , 111} may be used for the CS value for the sidelinkSSS.

For example, as shown in the following Equation 11, m₀={0, 5, 15, 20}may be used. Here, m₁={0, 1, . . . , 111} may be used for m₀={0, 5}, andm₁={0, 1, . . . , 55} may be used for m₀={15, 20}. Therefore, a numberof possible combinations of m₀ and m₁ may correspond to a total of 336(=2*112+2*56) SLIDs.

d _(SSS)(n)=[1−2x ₀((n+m ₀)mod127)][1−2x ₁((n+m ₁)mod127)]

m ₀=15└N _(ID) ⁽¹⁾/112┘+5N _(ID) ⁽²⁾

m ₁ =N _(ID) ⁽¹⁾mod112

0≤n<127  [Equation 11]

As an additional example, as shown in the following Equation 12, m₀={0,5, 10, 15} may be used. Here, m₁={0, 1, . . . , 111} may be used form₀={0, 5} and m₁={0, 1, . . . , 55} may be used for m₀={10, 15}.Therefore, a number of possible combinations of m₀ and m₁ may correspondto a total of 336 (=2*112+2*56) SLIDs.

d _(SSS)(n)=[1−2x ₀((n+m ₀)mod127)][1−2x ₁((n+m ₁)mod127)]

m ₀=10└N _(ID) ⁽¹⁾/112┘+5N _(ID) ⁽²⁾

m ₁ =N _(ID) ⁽¹⁾mod112

0≤n<127  [Equation 12]

As an additional example, as shown in the following Equation 13, m₀={0,5, 15, 20} and m₁={0, 1, . . . , 83} may be used. Therefore, a number ofpossible combinations of m₀ and m₁ may correspond to a total of 336(=4*84) SLIDs.

d _(SSS)(n)=[1−2x ₀((n+m ₀)mod127)][1−2x ₁((n+m ₁)mod127)]

m ₀=15└N _(ID) ⁽¹⁾/84┘+5N _(ID) ⁽²⁾

m ₁ =N _(ID) ⁽¹⁾mod84  [Equation 13]

As an additional example, as shown in the following Equation 14, m₀={0,5, 10, 15} and m₁={0, 1, . . . , 83} may be used. Therefore, a number ofpossible combinations of m₀ and m₁ may correspond to a total of 336(=4*84) SLIDs.

d _(SSS)(n)=[1−2x ₀((n+m ₀)mod127)][1−2x ₁((n+m ₁)mod127)]

m ₀=10└N _(ID) ⁽¹⁾/84┘+5N _(ID) ⁽²⁾

m ₁ =N _(ID) ⁽¹⁾mod84

0≤n<127  [Equation 14]

Examples A1, B1, and C2

Sidelink PSS Resource (Example C2-PSS)

A primitive polynomial and an initialization value for a sidelink PSSmay be applied to be identical to those for a downlink PSS. Here, a CSvalue for the sidelink PSS may use a portion of CS values for thedownlink PSS.

For example, although the same primitive polynomial and initializationvalue as Equation 8 apply to the sidelink PSS, the CS value for thesidelink PSS may be defined as CS=0 if N_(ID) ⁽²⁾=0 and CS=43 if N_(ID)⁽²⁾=1.

Sidelink SSS Resource (Example C2-SSS)

A primitive polynomial and an initialization value for a sidelink SSSmay be applied to be identical to those for a downlink SSS. Here, a CSvalue for the sidelink SSS may be applied to be different from a CSvalue for the downlink SSS.

That is, the primitive polynomial of Equation 9 may apply to thesidelink SSS and the CS value may be applied to be different from the CSvalue of the downlink SSS as follows.

For example, as shown in the following Equation 15, m₀={0+k, 5+k, 15+k,20+k} may be used. Here, m₁={0, 1, . . . , 111} may be used for m₀={0+k,5+k} and m₁={0, 1, . . . , 55} may be used for m₀={15+k, 20+k}.Therefore, a number of possible combinations of m₀ and m₁ may correspondto a total of 336 (=2*112+2*56) SLIDs. Here, although a value of k=45may be given, it is provided as an example only. For example, k may be avalue that satisfies 20+k<112 among multiples of 5, greater than 40(e.g., one of k={45, 50, 55, . . . , 90}).

d _(SSS)(n)=[1−2x ₀((n+m ₀)mod127)][1−2x ₁((n+m ₁)mod127)]

m ₀=15+5N _(ID) ⁽²⁾ +k

m ₁ =N _(ID) ⁽¹⁾mod112

0≤n<127  [Equation 15]

As an additional example, as shown in the following Equation 16,m₀={0+k, 5+k, 10+k, 15+k} may be used. Here, m₁={0, 1, . . . , 111} maybe used for m₀={0+k, 5+k} and └N_(ID) ⁽¹⁾/112┘ m₁={0, 1, . . . , 55} maybe used for m₀={10+k, 15+k}. Therefore, a number of possiblecombinations of m₀ and m₁ may correspond to a total of 336 (=2*112+2*56)SLIDs. Here, although a value of k=45 may be given, it is provided as anexample only. For example, k may be a value that satisfies 15+k<112among multiples of 5, greater than 40 (e.g., one of k={45, 50, 55, . . ., 95}).

d _(SSS)(n)=[1−2x ₀((n+m ₀)mod127)][1−2x ₁((n+m ₁)mod127)]

m ₀=10└N _(ID) ⁽¹⁾/112┘+5N _(ID) ⁽²⁾

m ₁ =N _(ID) ⁽¹⁾mod112

0≤n<127  [Equation 16]

As an additional example, as shown in the following Equation 17,m₀={0+k, 5+k, 15+k, 20+k} and m₁={0, 1, . . . , 83} may be used.Therefore, a number of possible combinations of m₀ and m₁ may correspondto a total of 336 (=4*84) SLIDs. Here, although a value of k=45 may begiven, it is provided as an example only. For example, k may be a valuethat satisfies 20+k<112 among multiples of 5, greater than 40 (e.g., oneof k={45, 50, 55, . . . , 90}).

d _(SSS)(n)=[1−2x ₀((n+m ₀)mod127)][1−2x ₁((n+m ₁)mod127)]

m ₀=15└N _(ID) ⁽¹⁾/84┘+5N _(ID) ⁽²⁾ +k

m ₁ =N _(ID) ⁽¹⁾mod84  [Equation 17]

As an additional example, as shown in the following Equation 18,m₀={0+k, 5+k, 10+k, 15+k} and m₁={0, 1, . . . , 83} may be used.Therefore, a number of possible combinations of m₀ and m₁ may correspondto a total of 336 (=4*84) SLIDs. Here, although a value of k=45 may begiven, it is provided as an example only. For example, k may be a valuethat satisfies 15+k<112 among multiples of 5, greater than 40 (e.g., oneof k={45, 50, 55, . . . , 95}).

d _(SSS)(n)=[1−2x ₀((n+m ₀)mod127)][1−2x ₁((n+m ₁)mod127)]

m ₀=10└N _(ID) ⁽¹⁾/84┘+5N _(ID) ⁽²⁾ +k

m ₁ =N _(ID) ⁽¹⁾mod84

0≤n<127  [Equation 18]

Accordingly, a value distinguished from the CS value applied to thedownlink SSS and corresponding to a farthest distance (e.g., as far ask) may be applied as the CS value applied to the sidelink SSS.

Examples A1, B1, and C3

Sidelink PSS Resource (Example C3-PSS)

As shown in Equation 8 and Equation 9, one (e.g., a polynomialcorresponding to octal 221 of Table 5) of first and second primitivepolynomials (e.g., polynomials corresponding to octal 221 and 203 ofTable 5) for a downlink SSS may be used as a primitive polynomial for adownlink PSS.

A primitive polynomial for a sidelink PSS may use another singleprimitive polynomial (e.g., a polynomial corresponding to octal 203 ofTable 5) distinguished from the primitive polynomial applied to thedownlink PSS among first and second primitive polynomials for a sidelinkSSS.

In this case, an initialization value for a sidelink PSS primitivepolynomial may be applied to be identical to an initialization value fora downlink PSS primitive polynomial. Alternatively, another singleinitialization value may be applied.

For example, the primitive polynomial for the sidelink PSS may bedefined as represented by the following Equation 19.

x(i+7)=(x(i+1)+x(i))mod2

[x(6)x(5)x(4)x(3)x(2)x(1)x(0)]=[1 1 1 0 1 1 0]  [Equation 19]

Here, a CS value for the sidelink PSS may use a portion of CS values forthe downlink PSS. For example, the CS value for the sidelink PSS may bedefined as CS=0 if N_(ID) ⁽²⁾=0 and CS=43 if N_(ID) ⁽²⁾=1.

Sidelink SSS Resource (Example C3-SSS)

Although a primitive polynomial for a sidelink SSS may use the samepolynomial as that for a downlink SSS, first and second primitivepolynomials may be replaced with each other. For example, if first andsecond primitive polynomials applied to the downlink SSS are defined aspolynomials corresponding to octal 221 and 203 of Table 5, respectively(see Equation 9), first and second primitive polynomials applied to thesidelink SSS may be defined as polynomials corresponding to octal 203and 221 of Table 5, respectively.

For example, the first and second primitive polynomials for the sidelinkSSS may be defined as the following Equation 20.

x ₀(i+7)=(x ₀(i+1)+x ₀(i))mod2

x ₁(i+7)=(x ₁(i+4)+x ₁(i))mod2

[x ₀(6)x ₀(5)x ₀(4)x ₀(3)x ₀(2)x ₀(1)x ₀(0)]=[0 0 0 0 0 0 1]

[x ₁(6)x ₁(5)x ₁(4)x ₁(3)x ₁(2)x ₁(1)x ₁(0)]=[0 0 0 0 0 0 1]  [Equation20]

In this case, an initialization value for a sidelink SSS primitivepolynomial may be applied to be identical to an initialization value fora downlink SSS primitive polynomial. Alternatively, another singleinitialization value may be applied.

Here, a CS value for the sidelink SSS may use a portion of CS values forthe downlink SSS.

That is, the primitive polynomial of Equation 20 may be applied to thesidelink SSS and a portion of m₀={0, 5, 10, 15, 20, 25, 30, 35, 40} andm₁={0, 1, . . . , 111} may be used as the CS value for the sidelink SSS.

For example, as shown in the above Equation 11, m₀={0, 5, 15, 20} may beused. Here, m₁={0, 1, . . . , 111} may be used for m₀={0, 5} and m₁={0,1, . . . , 55} may be used for m₀={15, 20}. Therefore, a number ofpossible combinations of m₀ and m₁ may correspond to a total of 336(=2*112+2*56) SLIDs.

As an additional example, as shown in the above Equation 12, m₀={0, 5,10, 15} may be used. Here, m₁={0, 1, . . . , 111} may be used for m₀={0,5}, and m₁={0, 1, . . . , 55} may be used for m₀={10, 15}. Therefore, anumber of possible combinations of m₀ and m₁ may correspond to a totalof 336 (=2*112+2*56) SLIDs.

As an additional example, as shown in the above Equation 13, m₀={0, 5,15, 20} and m₁={0, 1, . . . , 83} may be used. Therefore, a number ofpossible combinations of m₀ and m₁ may correspond to a total of 336(=4*84) SLIDs.

As an additional example, as shown in the above Equation 14, m₀={0, 5,10, 15} and m₁={0, 1, . . . , 83} may be used. Therefore, a number ofpossible combinations of m₀ and m₁ may correspond to a total of 336(=4*84) SLIDs.

Examples A1, B1, and C4

In the present example, first and second primitive polynomials differentfrom those applied to a downlink SSS may be applied to a sidelink SSS.Also, one of the first and second primitive polynomials for the sidelinkSSS may be applied as a primitive polynomial for a sidelink PSS.Therefore, the first and second primitive polynomials used for thedownlink PSS and the downlink SSS and the first and second primitivepolynomials used for the sidelink PSS and the sidelink SSS may notoverlap.

For example, primitive polynomials used for the sidelink PSS and thesidelink SSS may be defined as primitive polynomials belonging to thesame maximum connected set (see Table 6).

Sidelink PSS Resource (Example C4-PSS)

As a primitive polynomial for a sidelink PSS, one of remaining primitivepolynomials excluding primitive polynomials used for a downlink PSS anda downlink SSS from among polynomials belonging to set 5 included inprimitive polynomials (221 and 203 represented using an octal system)used for the downlink PSS and the downlink SSS in the maximum connectedset of Table 6 may be selected. For example, one of polynomials 253,271, 367, and 345 represented using an octal system may be selected asthe primitive polynomial for the sidelink PSS.

For example, as shown in the following Equation 21, a polynomialcorresponding to octal 253 may be applied as the primitive polynomialfor the sidelink PSS. In this case, an initialization value for asidelink PSS primitive polynomial may be applied to be identical to aninitialization value for a downlink PSS primitive polynomial.Alternatively, another single initialization value may be applied.

x(i+7)=(x(i+5)+x(i+3)+x(i+1)+x(i))mod2

[x(6)x(5)x(4)x(3)x(2)x(1)x(0)]=[1 1 1 0 1 1 0]  [Equation 21]

Here, a CS value for the sidelink PSS may use a portion of CS values forthe downlink PSS. For example, the CS value for the sidelink PSS may bedefined as CS=0 if N_(ID) ⁽²⁾=0 and CS=43 if N_(ID) ⁽²⁾=1.

Sidelink SSS Resource (Example C4-SSS)

The same primitive polynomial as a primitive polynomial for a sidelinkPSS may be selected as a first primitive polynomial for a sidelink SSS,and one of polynomials belonging to the same maximum connected set tothat of the first primitive polynomial may be selected as a secondprimitive polynomial for the sidelink SSS.

For example, a single polynomial applied to the sidelink PSS amongpolynomials corresponding to octal 253, 271, 367, and 345 belonging tothe maximum connected set 5 of Table 6 and a remaining single polynomialamong the polynomials may be applied as primitive polynomials for thesidelink SSS. For example, if a polynomial corresponding to octal 253 isapplied to the sidelink PSS, 253 and 271, 253 and 367, or 253 and 345may be applied as the first and second primitive polynomials for thesidelink SSS.

For example, as shown in the following Equation 22, polynomialscorresponding to octal 253 and 271 may be applied as the first andsecond primitive polynomials for the sidelink SSS. In this case, aninitialization value for a sidelink PSS primitive polynomial may beapplied to be identical to an initialization value for a downlink SSSprimitive polynomial. Alternatively, another single initialization valuemay be applied.

x ₀(i+7)=(x ₀(i+5)+x ₀(i+3)+x ₀(i+1)+x ₀(i))mod2

x ₁(i+7)=(x ₁(i+5)+x ₁(i+4)+x ₁(i+3)+x ₁(i))mod2

[x ₀(6)x ₀(5)x ₀(4)x ₀(3)x ₀(2)x ₀(1)x ₀(0)]=[0 0 0 0 0 0 1]

[x ₁(6)x ₁(5)x ₁(4)x ₁(3)x ₁(2)x ₁(1)x ₁(0)]=[0 0 0 0 0 0 1]  [Equation22]

Here, a CS value for the sidelink SSS may use a portion of CS values forthe downlink SSS.

That is, the first and second primitive polynomials as shown in Equation22 or an additional example may be applied to the sidelink SSS, and aportion of m₀={0, 5, 10, 15, 20, 25, 30, 35, 40} and m₁={0, 1, . . . ,111} may be used as the CS value for the sidelink SSS.

For example, as shown in the above Equation 11, m₀={0, 5, 15, 20} may beused. Here, m₁={0, 1, . . . , 111} may be used for m₀={0, 5} and m₁={0,1, . . . , 55} may be used for m₀={15, 20}. Therefore, a number ofpossible combinations of m₀ and m₁ may correspond to a total of 336(=2*112+2*56) SLIDs.

As an additional example, as shown in the above Equation 12, m₀={0, 5,10, 15} may be used. Here, m₁={0, 1, . . . , 111} may be used for m₀={0,5} and m₁={0, 1, . . . , 55} may be used for m₀={10, 15}. Therefore, anumber of possible combinations of m₀ and m₁ may correspond to a totalof 336 (=2*112+2*56) SLIDs.

As an additional example, as shown in the above Equation 13, m₀={0, 5,15, 20} and m₁={0, 1, . . . , 83} may be used. Therefore, a number ofpossible combinations of m₀ and m₁ may correspond to a total of 336(=4*84) SLIDs.

As an additional example, as shown in Equation 14, m₀={0, 5, 10, 15} andm₁={0, 1, . . . , 83} may be used. Therefore, a number of possiblecombinations of m₀ and m₁ may correspond to a total of 336 (=4*84)SLIDs.

Examples A1, B1, C1, and C2

The present example describes an example of distinguishing a sidelinksynchronization signal sequence from an NR downlink synchronizationsignal sequence by applying a different resource of a sidelink PSS or asidelink SSS with respect to each type of a physical layer sidelinksynchronization identity set (e.g., id_net and id_oon).

For example, with respect to id_net, a CS value for the sidelink SSS maybe applied to be different from a CS value for a downlink SSS. Also,with respect to id_oon, a CS value for the sidelink PSS may be appliedto be different from a CS value for the downlink PSS.

Sidelink PSS Resource (Example C1+C2-PSS)

A primitive polynomial and an initialization value for a sidelink PSSmay be applied to be identical to those for a downlink PSS. Here, withrespect to id_oon, a CS value for the sidelink PSS may be applied to bedifferent from a CS value for the downlink PSS. Also, with respect toid_net, the CS value for the sidelink PSS may use a portion of CS valuesfor the downlink PSS.

For example, although the same primitive polynomial and initializationvalue as Equation 8 may be applied to the sidelink PSS, the CS value forthe sidelink PSS may be defined as CS=0 if N_(ID) ⁽²⁾=0 (i.e., in thecase of id_net) and CS=43+k if N_(ID) ⁽²⁾=1 (i.e., in the case ofid_oon) as represented by the following Equation 23. Here, although avalue of k=21 or 22 may be given, it is provided as an example only.

d _(PSS)(n)=1−2x(m)

m=(n+(43+k)N _(ID) ⁽²⁾)mod127

0≤n<127  [Equation 23]

Sidelink SSS Resource (Example C1+C2-SSS)

A primitive polynomial and an initialization value for a sidelink SSSmay be applied to be identical to those for a downlink SSS. Here, withrespect to id_net, a CS value for the sidelink SSS may be applied to bedifferent from a CS value for the downlink SSS. Also, with respect toid_oon, the CS value for the sidelink SSS may use a portion of CS valuesfor the downlink SSS.

That is, the primitive polynomial of Equation 9 may be applied to thesidelink SSS and the CS value may be applied as shown in the followingexamples.

For example, as shown in the following Equation 24, if N_(ID) ⁽²⁾=1(i.e., in the case of id_oon), m₀={0, 15}, and if N_(ID) ⁽²⁾=0 (i.e., inthe case of id_net), m₀={0+k, 15+k}. Also, m₁={0, 1, . . . , 111} may beused for m₀={0, 0+k} and m₁={0, 1, . . . , 55} may be used for m₀={15,15+k}. Therefore, a number of possible combinations of m₀ and m₁ maycorrespond to a total of 336 (=2*112+2*56) SLIDs. Here, although a valueof k=45 may be given, it is provided as an example only. For example, kmay be a value that satisfies 15+k<112 among multiples of 5, greaterthan 40 (e.g., one of k={45, 50, 55, . . . , 95}).

d _(SSS)(n)=[1−2x ₀((n+m ₀)mod127)][1−2x ₁((n+m ₁)mod127)]

m ₀=15└N _(ID) ⁽¹⁾/112┘+(1−N _(ID) ⁽²⁾)·k

m ₁ =N _(ID) ⁽¹⁾mod112

0≤n<127  [Equation 24]

As an additional example, as shown in the following Equation 25, ifN_(ID) ⁽²⁾=1, (i.e., in the case of id_oon), m₀={0, 5}, and if N_(ID)⁽²⁾=0 (i.e., in the case of id_net), m₀={0+k, 5+k}. Also, m₁={0, 1, . .. , 111} may be used for m₀={0, 0+k}, and m₁={0, 1, . . . , 55} may beused for m₀={5, 5+k}. Therefore, a number of possible combinations of m₀and m₁ may correspond to a total of 336 (=2*112+2*56) SLIDs. Here,although a value of k=45 may be given, it is provided as an exampleonly. For example, k may be a value that satisfies 5+k<112 amongmultiples of 5, greater than 40 (e.g., one of k={45, 50, 55, . . . ,105}).

d _(SSS)(n)=[1−2x ₀((n+m ₀)mod127)][1−2x ₁((n+m ₁)mod127)]

m ₀=5└N _(ID) ⁽¹⁾/112┘+(1−N _(ID) ⁽²⁾)·k

m ₁ =N _(ID) ⁽¹⁾mod112

0≤n<127  [Equation 25]

As an additional example, as shown in the following Equation 26, ifN_(ID) ⁽²⁾=1 (i.e., in the case of id_oon), m₀={0, 15}, and if N_(ID)⁽²⁾=0 (i.e., in the case of id_net), m₀={0+k, 15+k}. Also, m₁={0, 1, . .. , 83} may be used for m₀={0, 0+k, 15, 15+k}. Therefore, a number ofpossible combinations of m₀ and m₁ may correspond to a total of 336(=4*84) SLIDs. Here, although a value of k=45 may be given, it isprovided as an example only. For example, k may be a value thatsatisfies 15+k<112 among multiples of 5, greater than 40 (e.g., one ofk={45, 50, 55, . . . , 95}).

d _(SSS)(n)=[1−2x ₀((n+m ₀)mod127)][1−2x ₁((n+m ₁)mod127)]

m ₀=15└N _(ID) ⁽¹⁾/84┘+(1−N _(ID) ⁽²⁾)·k

m ₁ =N _(ID) ⁽¹⁾mod84

0≤n<127  [Equation 26]

As an additional example, as shown in the following Equation 27, ifN_(ID) ⁽²⁾=1 (i.e., in the case of id_oon), m₀={0, 5}, and if N_(ID)⁽²⁾=0 (i.e., in the case of id_net), m₀={0+k, 5+k}. Also, m₁={0, 1, . .. , 83} may be used for m₀={0, 0+k, 5, 5+k}. Therefore, a number ofpossible combinations of m₀ and m₁ may correspond to a total of 336(=4*84) SLIDs. Here, although a value of k=45 may be given, it isprovided as an example only. For example, k may be a value thatsatisfies 5+k<112 among multiples of 5, greater than 40 (e.g., one ofk={45, 50, 55, . . . , 105}).

d _(SSS)(n)=[1−2x ₀((n+m ₀)mod127)][1−2x ₁((n+m ₁)mod127)]

m ₀=5└N _(ID) ⁽¹⁾/84┘+(1−N _(ID) ⁽²⁾)·k

m ₁ =N _(ID) ⁽¹⁾mod84

0≤n<127  [Equation 27]

Examples A1 and B2

A physical layer sidelink synchronization identity set may be definedinto two types, that is, id_net and id_oon, and each of id_net andid_oon may include 336 sequences and may be defined as follows:

id_net={0,1, . . . ,335}

id_oon={336,337, . . . ,671}

N _(ID) ^(SL)={0,1, . . . ,671}

N _(ID) ⁽¹⁾ =N _(ID) ^(SL)mod336

N _(ID) ⁽²⁾=int(N _(ID) ^(SL)/336),N _(ID) ⁽²⁾={0,1}

Examples A1, B2, and C1

A primitive polynomial and an initialization value for a sidelink PSSmay be applied to be identical to those for a downlink PSS. Here, a CSvalue for the sidelink PSS may be applied to be different from a CSvalue for the downlink PSS. The present example corresponds to exampleC1-PSS among the aforementioned combinations of examples A1, B1, and C1and thus, a further description is omitted.

A primitive polynomial and an initialization value for a sidelink SSSmay be applied to be identical to those for a downlink SSS. Here, a CSvalue for the sidelink SSS may use a portion of CS values for thedownlink SSS. The present example corresponds to example C1-SSS amongthe aforementioned combinations of examples A1, B1, and C1 and thus, afurther description is omitted. Here, examples of the present exampleabout a CS value of the sidelink SSS are described.

For example, as shown in the above Equation 11, if a CS for a sidelinkSSS is applied, m₀={0, 5, 15, 20, 30, 35} and m₁={0, 1, . . . , 111} maybe used. Therefore, a number of possible combinations of m₀ and m₁ maycorrespond to a total of 672 (=6*112) SLIDs.

As an additional example, as shown in the above Equation 12, if a CS fora sidelink SSS is applied, m₀={0, 5, 10, 15, 20, 25} and m₁={0, 1, . . ., 111} may be used. Therefore, a number of possible combinations of m₀and m₁ may correspond to a total of 672 (=6*112) SLIDs.

Examples A1, B2, and C2

A primitive polynomial and an initialization value for a sidelink PSSmay be applied to be identical to those for a downlink PSS. Here, a CSvalue for the sidelink PSS may use a portion of CS values for thedownlink PSS. The present example corresponds to example C2-PSS amongthe aforementioned combinations of examples A1, B1, and C2 and thus, afurther description is omitted.

A primitive polynomial and an initialization value for a sidelink SSSmay be applied to be identical to those for a downlink SSS. Here, a CSvalue for the sidelink SSS may be applied to be different from a CSvalue for the downlink SSS. The present example corresponds to exampleC2-SSS among the aforementioned combinations of examples A1, B1, and C2and thus, a further description is omitted. Here, examples of thepresent example about a CS value of the sidelink SSS are described.

For example, as shown in the above Equation 15, m₀={0+k, 5+k, 15+k,20+k, 30+k, 35+k} and m₁={0, 1, . . . , 111} may be used. Therefore, anumber of possible combinations of m₀ and m₁ may correspond to a totalof 672 (=6*112) SLIDs. Here, although a value of k=45 may be given, itis provided as an example only. For example, k may be a value thatsatisfies 35+k<112 among multiples of 5, greater than 40 (e.g., one ofk={45, 50, 55, . . . , 75}).

As an additional example, as shown in the above Equation 16, m₀={0+k,5+k, 10+k, 15+k, 20+k, 25+k} and m₁={0, 1, . . . , 111} may be used.Therefore, a number of possible combinations of m₀ and m₁ may correspondto a total of 672 (=6*112) SLIDs. Here, although a value of k=45 may begiven, it is provided as an example only. For example, k may be a valuethat satisfies 25+k<112 among multiples of 5, greater than 40 (e.g., oneof k={45, 50, 55, . . . , 85}).

Examples A1, B2, and C3

A primitive polynomial for a sidelink PSS may use another singleprimitive polynomial (e.g., a polynomial corresponding to octal 203 ofTable 5) distinguished from a primitive polynomial applied to a downlinkPSS among first and second primitive polynomials for a sidelink SSS. Thepresent example corresponds to example C3-PSS among the aforementionedcombinations of examples A1, B1, and C3 and thus, a further descriptionis omitted.

Although a primitive polynomial and an initialization value for thesidelink SSS may use the same polynomial as that for a downlink SSS,first and second primitive polynomials may be replaced with each other.For example, if first and second primitive polynomials applied to thedownlink SSS are defined as polynomials corresponding to octal 221 and203 of Table 5, respectively (see Equation 9), first and secondprimitive polynomials applied to the sidelink SSS may be defined aspolynomials corresponding to octal 203 and 221 of Table 5, respectively.The present example corresponds to example C3-SSS among theaforementioned combinations of examples A1, B1, and C3 and thus, afurther description is omitted. Here, examples of the present exampleabout a CS value of the sidelink SSS are described.

For example, as shown in the above Equation 11, m₀={0, 5, 15, 20, 30,35} and m₁={0, 1, . . . , 111} may be used. Therefore, a number ofpossible combinations of m₀ and m₁ may correspond to a total of 672(=6*112) SLIDs.

As an additional example, as shown in the above Equation 12, m₀={0, 5,10, 15, 20, 25} and m₁={0, 1, . . . , 111} may be used. Therefore, anumber of possible combinations of m₀ and m₁ may correspond to a totalof 672 (=6*112) SLIDs.

Examples A1, B2, and C4

In the present example, first and second primitive polynomials differentfrom those applied to a downlink SSS may be applied to a sidelink SSS.Also, one of the first and second primitive polynomials for the sidelinkSSS may be applied as a primitive polynomial for a sidelink PSS.Therefore, first and second primitive polynomials used for a downlinkPSS and the downlink SSS and first and second primitive polynomials usedfor the sidelink PSS and the sidelink SSS may not overlap.

For example, primitive polynomials used for the sidelink PSS and thesidelink SSS may be defined as primitive polynomials belonging to thesame maximum connected set (see Table 6).

The present example of selecting a primitive polynomial for the sidelinkPSS from the maximum connected set of Table 6 corresponds to exampleC4-PSS among the aforementioned combinations of examples A1, B1, and C4and thus, a further description is omitted.

The same primitive polynomial as a primitive polynomial for a sidelinkPSS may be selected as a first primitive polynomial for the sidelinkSSS, and one of polynomials belonging to the same maximum connected setas that of the first primitive polynomial may be selected as a secondprimitive polynomial for the sidelink SSS. The present examplecorresponds to example C4-SSS among the aforementioned combinations ofexamples A1, B1, and C4 and thus, a further description is omitted here.Here, examples of the present example about a CS value of the sidelinkSSS are described.

For example, as shown in the above Equation 11, m₀={0, 5, 15, 20, 30,35} and m₁={0, 1, . . . , 111} may be used. Therefore, a number ofpossible combinations of m₀ and m₁ may correspond to a total of 672(=6*112) SLIDs.

As an additional example, as shown in the above Equation 12, m₀={0, 5,10, 15, 20, 25} and m₁={0, 1, . . . , 111} may be used. Therefore, anumber of possible combinations of m₀ and m₁ may correspond to a totalof 672 (=6*112) SLIDs.

Examples A1, B2, C1, and C2

The present example describes an example of distinguishing a sidelinksynchronization signal sequence from an NR downlink synchronizationsignal sequence by applying a different resource of a sidelink PSS or asidelink SSS with respect to each type of a physical layer sidelinksynchronization identity set (e.g., id_net and id_oon).

For example, with respect to id_net, a CS value for the sidelink SSS maybe applied to be different from a CS value for a downlink SSS. Also,with respect to id_oon, a CS value for the sidelink PSS may be appliedto be different from a CS value for a downlink PSS.

The example of the present example of applying a CS value for thesidelink PSS to be different from a CS value for the downlink PSS withrespect to id_oon and using a portion of CS values for the downlink PSSas a CS value for the sidelink PSS with respect to id_net corresponds toexample C1+C2-PSS among the aforementioned combinations of examples A1,B1, C1, and C2 and thus, a further description is omitted.

Also, the example of applying a CS value for the sidelink SSS to bedifferent from a CS value for the downlink SSS with respect to id_netand using a portion of CS values for the downlink SSS as a CS value forthe sidelink SSS with respect to id_oon corresponds to example C1+C2-SSSamong the aforementioned combinations of examples A1, B1, C1, and C2 andthus, a further description is omitted. Here, examples of the presentexample about a CS value of the sidelink SSS are described.

For example, as shown in the above Equation 24, if N_(ID) ⁽²⁾=1 (i.e.,in the case of id_oon), m₀={0, 15, 30}, and if N_(ID) ⁽²⁾=0 (i.e., inthe case of id_net), m₀={0+k, 15+k, 30+k}. Also, m₁={0, 1, . . . , 111}may be used for m₀={0, 0+k, 15, 15+k, 30, 30+k}. Therefore, a number ofpossible combinations of m₀ and m₁ may correspond to a total of 672(=6*112) SLIDs. Here, although a value of k=45 may be given, it isprovided as an example only. For example, k may be a value thatsatisfies 30+k<112 among multiples of 5, greater than 40 (e.g., one ofk={45, 50, 55, . . . , 80}).

As an additional example, as shown in the above Equation 25, if N_(ID)⁽²⁾=1 (i.e., in the case of id_oon), m₀={0, 5, 10}, and if N_(ID) ⁽²⁾=0(i.e., in the case of id_net), m₀={0+k, 5+k, 10+k}. Also, m₁={0, 1, . .. , 1111 may be used for m₀=10, 0+k, 5, 5+k, 10, 10+k}. Therefore, anumber of possible combinations of m₀ and m₁ may correspond to a totalof 672 (=6*112) SLIDs. Here, although a value of k=45 may be given, itis provided as an example only. For example, k may be a value thatsatisfies 10+k<112 among multiples of 5, greater than 40 (e.g., one ofk=145, 50, 55, . . . , 1001).

Examples A1 and B3

A physical layer sidelink synchronization identity set may be definedinto two types, that is, id_net and id_oon, and each of id_net andid_oon may include 504 sequences and may be defined as follows:

id_net={0,1, . . . ,503}

id_oon={504,505, . . . ,1007}

N _(ID) ^(SL)={0,1, . . . ,1007}

N _(ID) ⁽¹⁾ =N _(ID) ^(SL)mod504

N _(ID) ⁽²⁾=int(N _(ID) ^(SL)/504),N _(ID) ⁽²⁾={0,1}

Examples A1, B3, and C1

A primitive polynomial and an initialization value for a sidelink PSSmay be applied to be identical to those for a downlink PSS. Here, a CSvalue for the sidelink PSS may be applied to be different from a CSvalue for the downlink PSS. The present example corresponds to exampleC1-PSS among the aforementioned combinations of examples A1, B1, and C1and thus, a further description is omitted.

A primitive polynomial and an initialization value for a sidelink SSSmay be applied to be identical to those for a downlink SSS. Here, a CSvalue for the sidelink SSS may be applied to be different from a CSvalue for the downlink SSS. The present example is identical to exampleC1-SSS among the aforementioned combinations of examples A1, B1, and C1in terms of the primitive polynomial and the initialization value forthe sidelink SSS and different therefrom in terms of examples of the CSvalue of the sidelink SSS. Therefore, a further description related tothe corresponding description is omitted and examples of the presentexample about a CS value of the sidelink SSS are described.

For example, as shown in the above Equation 11, if a CS for a sidelinkSSS is applied, m₀={0, 5, 15, 20, 30, 35, 45, 50, 60, 65} may be used.Here, m₁={0, 1, . . . , 111} may be used for m₀={0, 5, 15, 20, 30, 35,45, 50} and m₁={0, 1, . . . , 55} may be used for m₀={60, 65}.Therefore, a number of possible combinations of m₀ and m₁ may correspondto a total of 1008 (=8*112+2*56) SLIDs.

As an additional example, as shown in the above Equation 12, m₀={0, 5,10, 15, 20, 25, 30, 35, 40, 45} may be used. Here, m₁={0, 1, . . . ,111} may be used for m₀ and m₁={0, 1, . . . , 55} may be used form₀=140, 451. Therefore, a number of possible combinations of m₀ and m₁may correspond to a total of 1008 (=8*112+2*56) SLIDs.

As an additional example, as shown in the above Equation 13, m₀={0, 5,15, 20, 30, 35, 45, 50, 60, 65, 75, 80} and m₁={0, 1, . . . , 83} may beused. Therefore, a number of possible combinations of m₀ and m₁ maycorrespond to a total of 1008 (=12*84) SLIDs.

As an additional example, as shown in the above Equation 14, m₀={0, 5,10, 15, 20, 25, 30, 35, 40, 45, 50, 55} and m₁={0, 1, . . . , 83} may beused. Therefore, a number of possible combinations of m₀ and m₁ maycorrespond to a total of 1008 (=12*84) SLIDs.

Examples A1, B3, and C2

A primitive polynomial and an initialization value for a sidelink PSSmay be applied to be identical to those for a downlink PSS. Here, a CSvalue for the sidelink PSS may use a portion of CS values for thedownlink PSS. The present example corresponds to example C2-PSS amongthe aforementioned combinations of examples A1, B1, and C2 and thus, afurther description is omitted here.

A primitive polynomial and an initialization value for a sidelink SSSmay be applied to be identical to those for a downlink SSS. Here, a CSvalue for the sidelink SSS may be applied to be different from a CSvalue for the downlink SSS. The present example corresponds to exampleC2-SSS among the aforementioned combinations of examples A1, B1, and C2and thus, a further description is omitted. Here, examples of thepresent example about a CS value of the sidelink SSS are described.

For example, as shown in the above Equation 15, m₀={0+k, 5+k, 15+k,20+k, 30+k, 35+k, 45+k, 50+k, 60+k, 65+k} may be used. Here, m₁={0, 1, .. . , 1111 may be used for m₀={0+k, 5+k, 15+k, 20+k, 30+k, 35+k, 45+k,50+k} and m₁={0, 1, . . . , 55} may be used for m₀={60+k, 65+k}.Therefore, a number of possible combinations of m₀ and m₁ may correspondto a total of 1008 (=8*112+2*56) SLIDs. Here, k=45 may be given. Forexample, k may be a value that satisfies 65+k<112 among multiples of 5,greater than 40.

As an additional example, as shown in the above Equation 16, m₀={0+k,5+k, 10+k, 15+k, 20+k, 25+k, 30+k, 35+k, 40+k, 45+k} may be used. Here,m₁={0, 1, . . . , 111} may be used for m₀={0+k, 5+k, 10+k, 15+k, 20+k,25+k, 30+k, 35+k}, and m₁={0, 1, . . . , 55} may be used for m₀={40+k,45+k}. Therefore, a number of possible combinations of m₀ and m₁ maycorrespond to a total of 1008 (=8*112+2*56) SLIDs. Here, although avalue of k=45 may be given, it is provided as an example only. Forexample, k may be a value that satisfies 45+k<112 among multiples of 5,greater than 40 (e.g., one of k={45, 50, 55, 60, 65}).

As an additional example, as shown in the above Equation 18, m₀={0+k,5+k, 10+k, 15+k, 20+k, 25+k, 30+k, 35+k, 40+k, 45+k, 50+k, 55+k} andm₁={0, 1, . . . , 83} may be used. Therefore, a number of possiblecombinations of m₀ and m₁ may correspond to a total of 1008(=8*112+2*56) SLIDs. Here, although a value of k=45 may be given, it isprovided as an example only. For example, k may be a value thatsatisfies 55+k<112 among multiples of 5, greater than 40 (e.g., one ofk={45, 50, 55}).

Examples A1, B3, and C3

A primitive polynomial for a sidelink PSS may use another singleprimitive polynomial (e.g., a polynomial corresponding to octal 203 ofTable 5) distinguished from a primitive polynomial applied to a downlinkPSS among first and second primitive polynomials for a sidelink SSS. Thepresent example corresponds to example C3-PSS among the aforementionedcombinations of examples A1, B1, and C3 and thus, a further descriptionis omitted.

Although a primitive polynomial and an initialization value for thesidelink SSS may use the same polynomial as that for a downlink SSS,first and second primitive polynomials may be replaced with each other.For example, if first and second primitive polynomials applied to thedownlink SSS are defined as polynomials corresponding to octal 221 and203 of Table 5, respectively (see Equation 9), first and secondprimitive polynomials applied to the sidelink SSS may be defined aspolynomials corresponding to octal 203 and 221 of Table 5, respectively.The present example corresponds to example C3-SSS among theaforementioned combinations of examples A1, B1, and C3 and thus, afurther description is omitted. Here, examples of the present exampleabout a CS value of the sidelink SSS are described.

For example, as shown in the above Equation 11, m₀={0, 5, 15, 20, 30,35, 45, 50, 60, 65} may be used. Here, m₁={0, 1, . . . , 111} may beused for m₀={0, 5, 15, 20, 30, 35, 45, 50} and m₁={0, 1, . . . , 55} maybe used for m₀={60, 65}. Therefore, a number of possible combinations ofm₀ and m₁ may correspond to a total of 1008 (=8*112+2*56) SLIDs.

As an additional example, as shown in the above Equation 12, m₀={0, 5,10, 15, 20, 25, 30, 35, 40, 45} may be used. Here, m₁={0, 1, . . . ,111} may be used for m₀={0, 5, 10, 15, 20, 25, 30, 35} and m₁={0, 1, . .. , 55} may be used for m₀={40, 45}. Therefore, a number of possiblecombinations of m₀ and m₁ may correspond to a total of 1008(=8*112+2*56) SLIDs.

As an additional example, as shown in the above Equation 13, m₀={0, 10,15, 20, 30, 35, 45, 50, 60, 65, 75, 80} and m₁={0, 1, . . . , 83} may beused. Therefore, a number of possible combinations of m₀ and m₁ maycorrespond to a total of 1008 (=12*84) SLIDs.

As an additional example, as shown in the above Equation 14, m₀={0, 5,10, 15, 20, 25, 30, 35, 40, 45, 50, 55} and m₁={0, 1, . . . , 83} may beused. Therefore, a number of possible combinations of m₀ and m₁ maycorrespond to a total of 1008 (=12*84) SLIDs.

Examples A1, B3, and C4

In the present example, first and second primitive polynomials differentfrom those applied to a downlink SSS may be applied to a sidelink SSS.Also, one of the first and second primitive polynomials for the sidelinkSSS may be applied as a primitive polynomial for a sidelink PSS.Therefore, first and second primitive polynomials used for a downlinkPSS and the downlink SSS and first and second primitive polynomials usedfor the sidelink PSS and the sidelink SSS may not overlap.

For example, primitive polynomials used for the sidelink PSS and thesidelink SSS may be defined as primitive polynomials belonging to thesame maximum connected set (see Table 6).

The present example of selecting one of polynomials belonging to themaximum connected set of Table 6 as a primitive polynomial for thesidelink PSS corresponds to example C4-PSS among the aforementionedcombinations of examples A1, B1, and C4 and thus, a further descriptionis omitted.

The same primitive polynomial as a primitive polynomial for a sidelinkPSS may be selected as a first primitive polynomial for the sidelinkSSS, and one of polynomials belonging to the same maximum connected setas that of the first primitive polynomial may be selected as a secondprimitive polynomial for the sidelink SSS. The present examplecorresponds to example C4-SSS among the aforementioned combinations ofexamples A1, B1, and C4 and thus, a further description is omitted.Here, examples of the present example about a CS value of the sidelinkSSS are described.

For example, as shown in the above Equation 11, m₀={0, 5, 15, 20, 30,35, 45, 50, 60, 65} may be used. Here, m₁={0, 1, . . . , 111} may beused for m₀={0, 5, 15, 20, 30, 35, 45, 50} and m₁={0, 1, . . . , 55} maybe used for m₀={60, 65}. Therefore, a number of possible combinations ofm₀ and m₁ may correspond to a total of 1008 (=8*112+2*56) SLIDs.

As an additional example, as shown in the above Equation 12, m₀={0, 5,10, 15, 20, 25, 30, 35, 40, 45} may be used. Here, m₁={0, 1, . . . ,111} may be used for m₀={0, 5, 10, 15, 20, 25, 30, 35}, and m₁={0, 1, .. . , 55} may be used for m₀={40, 45}. Therefore, a number of possiblecombinations of m₀ and m₁ may correspond to a total of 1008(=8*112+2*56) SLIDs.

As an additional example, as shown in the above Equation 13, m₀={0, 10,15, 20, 30, 35, 45, 50, 60, 65, 75, 80} and m₁={0, 1, . . . , 83} may beused. Therefore, a number of possible combinations of m₀ and m₁ maycorrespond to a total of 1008 (=12*84) SLIDs.

As an additional example, as shown in the above Equation 14, m₀={0, 5,10, 15, 20, 25, 30, 35, 40, 45, 50, 55} and m₁={0, 1, . . . , 83} may beused. Therefore, a number of possible combinations of m₀ and m₁ maycorrespond to a total of 1008 (=12*84) SLIDs.

Examples A1, B3, C1, and C2

The present example describes an example of distinguishing a sidelinksynchronization signal sequence from an NR downlink synchronizationsignal sequence by applying a different resource of a sidelink PSS or asidelink SSS with respect to each type of a physical layer sidelinksynchronization identity set (e.g., id_net and id_oon).

For example, with respect to id_net, a CS value for the sidelink SSS maybe applied to be different from a CS value for a downlink SSS. Also,with respect to id_oon, a CS value for the sidelink PSS may be appliedto be different from a CS value for a downlink PSS.

The example of the present example of applying a CS value for thesidelink PSS to be different from a CS value for the downlink PSS withrespect to id_oon and using a portion of CS values for the downlink PSSas a CS value for the sidelink PSS with respect to id_net corresponds toexample C1+C2-PSS among the aforementioned combinations of examples A1,B1, C1, and C2 and thus, a further description is omitted.

Also, the example of applying a CS value for the sidelink SSS to bedifferent from a CS value for the downlink SSS with respect to id_netand using a portion of CS values for the downlink SSS as a CS value forthe sidelink SSS with respect to id_oon corresponds to example C1+C2-SSSamong the aforementioned combinations of examples A1, B1, C1, and C2 andthus, a further description is omitted. Here, examples of the presentexample about a CS value of the sidelink SSS are described.

For example, as shown in the above Equation 24, if N_(ID) ⁽²⁾=1 (i.e.,in the case of id_oon), m₀={0, 15, 30, 45, 60}, and if N_(ID) ⁽²⁾=0(i.e., in the case of id_net), m₀={0+k, 15+k, 30+k, 45+k, 60+k}. Also,m₁={0, 1, . . . , 111} may be used for m₀={0, 0+k, 15, 15+k, 30, 30+k,45, 45+k} and m₁={0, 1, . . . , 55} may be used for m₀={60, 60+k}.Therefore, a number of possible combinations of m₀ and m₁ may correspondto a total of 1008 (=8*112+2*56) SLIDs. Here, although a value of k=45may be given, it is provided as an example only. For example, k may be avalue that satisfies 60+k<112 among multiples of 5, greater than 40(e.g., one of k={45, 50}).

As an additional example, as shown in the above Equation 25, if N_(ID)⁽²⁾=1 (i.e., in the case of id_oon), m₀={0, 5, 10, 15, 20}, and ifN_(ID) ⁽²⁾=0 (i.e., in the case of id_net), m₀={0+k, 5+k, 10+k, 15+k,20+k}. Also, m₁={0, 1, . . . , 111} may be used for m₀={0, 0+k, 5, 5+k,10, 10+k, 15, 15+k}, and m₁={0, 1, . . . , 55} may be used for m₀={20,20+k}. Therefore, a number of possible combinations of m₀ and m₁ maycorrespond to a total of 1008 (=8*112+2*56) SLIDs. Here, although avalue of k=45 may be given, it is provided as an example only. Forexample, k may be a value that satisfies 20+k<112 among multiples of 5,greater than 40 (e.g., one of k=145, 50, 55, . . . , 901).

As an additional example, as shown in the above Equation 27, if N_(ID)⁽²⁾=1 (i.e., in the case of id_oon), m₀={0, 5, 10, 15, 20, 25}, and ifN_(ID) ⁽²⁾=0 (i.e., in the case of id_net), m₀={0+k, 5+k, 10+k, 15+k,20+k, 25+k}. Here, m₁={0, 1, . . . , 83} may be used for m₀={0, 0+k, 5,5+k, 10, 10+k, 15, 15+k, 20, 20+k, 25, 25+k}. Therefore, a number ofpossible combinations of m₀ and m₁ may correspond to a total of 1008(=12*84) SLIDs. Here, although a value of k=45 may be given, it isprovided as an example only. For example, k may be a value thatsatisfies 25+k<112 among multiples of 5, greater than 40 (e.g., one ofk={45, 50, 55, . . . , 85}).

Examples A1 and B4

A physical layer sidelink synchronization identity set may be definedinto two types, that is, id_net and id_oon, and each of id_net andid_oon may include 1008 sequences and may be defined as follows:

id_net={0,1, . . . ,1007}

id_oon={1008,1009, . . . ,2015}

N _(ID) ^(SL)={0,1, . . . ,2015}

N _(ID) ⁽¹⁾ =N _(ID) ^(SL)mod1008

N _(ID) ⁽²⁾=int(N _(ID) ^(SL)/1008),N _(ID) ⁽²⁾={0,1}

Examples A1, B4, and C1

A primitive polynomial and an initialization value for a sidelink PSSmay be applied to be identical to those for a downlink PSS. Here, a CSvalue for the sidelink PSS may be applied to be different from a CSvalue for the downlink PSS. The present example corresponds to exampleC1-PSS among the aforementioned combinations of examples A1, B1, and C1and thus, a further description is omitted.

A primitive polynomial and an initialization value for a sidelink SSSmay be applied to be identical to those for a downlink SSS. Here, a CSvalue for the sidelink SSS may be applied to be different from a CSvalue for the downlink SSS. The present example is identical to exampleC1-SSS among the aforementioned combinations of examples A1, B1, and C1in terms of the primitive polynomial and the initialization value forthe sidelink SSS and different therefrom in terms of examples of the CSvalue of the sidelink SSS. Therefore, a further description related tothe corresponding description is omitted and examples of the presentexample about a CS value of the sidelink SSS are described.

For example, as shown in the above Equation 12, m₀={0, 5, 10, 15, 20,25, 30, 35, 40, 45, 50, 55, 60, 65, 70, 75, 80, 85} and m₁={0, 1, . . ., 111} may be used. Therefore, a number of possible combinations of m₀and m₁ may correspond to a total of 2016 (=18*112) SLIDs.

Examples A1, B4, and C3

A primitive polynomial for a sidelink PSS may use another singleprimitive polynomial (e.g., a polynomial corresponding to octal 203 ofTable 5) distinguished from a primitive polynomial applied to a downlinkPSS among first and second primitive polynomials for a sidelink SSS. Thepresent example corresponds to example C3-PSS among the aforementionedcombinations of examples A1, B1, and C3 and thus, a further descriptionis omitted.

Although a primitive polynomial and an initialization value for thesidelink SSS may use the same polynomial as that for a downlink SSS,first and second primitive polynomial may be replaced with each other.For example, if first and second primitive polynomials applied to thedownlink SSS are defined as polynomials corresponding to octal 221 and203 of Table 5, respectively (see Equation 9), first and secondprimitive polynomials applied to the sidelink SSS may be defined aspolynomials corresponding to octal 203 and 221 of Table 5, respectively.The present example corresponds to example C3-SSS among theaforementioned combinations of examples A1, B1, and C3 and thus, afurther description is omitted. Here, examples of the present exampleabout a CS value of the sidelink SSS are described.

For example, as shown in the above Equation 12, m₀={0, 5, 10, 15, 20,25, 30, 35, 40, 45, 50, 55, 60, 65, 70, 75, 80, 85} and m₁={0, 1, . . ., 111} may be used. Therefore, a number of possible combinations of m₀and m₁ may correspond to a total of 2016 (=18*112) SLIDs.

Examples A1, B4, and C4

In the present example, first and second primitive polynomials differentfrom those applied to a downlink SSS may be applied to a sidelink SSS.Also, one of the first and second primitive polynomials for the sidelinkSSS may be applied as a primitive polynomial for a sidelink PSS.Therefore, first and second primitive polynomials used for a downlinkPSS and the downlink SSS and first and second primitive polynomials usedfor the sidelink PSS and the sidelink SSS may not overlap.

For example, primitive polynomials used for the sidelink PSS and thesidelink SSS may be defined as primitive polynomials belonging to thesame maximum connected set (see Table 6).

The present example of selecting one of polynomials belonging to themaximum connected set of Table 6 as a primitive polynomial for thesidelink PSS corresponds to example C4-PSS among the aforementionedcombinations of examples A1, B1, and C4 and thus, a further descriptionis omitted.

The same primitive polynomial as a primitive polynomial for a sidelinkPSS may be selected as a first primitive polynomial for the sidelinkSSS, and one of polynomials belonging to the same maximum connected setas that of the first primitive polynomial may be selected as a secondprimitive polynomial for the sidelink SSS. The present examplecorresponds to example C1-SSS among the aforementioned combinations ofexamples A1, B1, and C1 and thus, a further description is omitted.Here, examples of the present example about a CS value of the sidelinkSSS are described.

For example, as shown in the above Equation 12, m₀={0, 5, 10, 15, 20,25, 30, 35, 40, 45, 50, 55, 60, 65, 70, 75, 80, 85} and m₁={0, 1, . . ., 111} may be used. Therefore, a number of possible combinations of m₀and m₁ may correspond to a total of 2016 (=18*112) SLIDs.

Examples A1, B4, C1, and C2

The present example describes an example of distinguishing a sidelinksynchronization signal sequence from an NR downlink synchronizationsignal sequence using a different resource of a sidelink PSS or asidelink SSS with respect to each type of a physical layer sidelinksynchronization identity set (e.g., id_net and id_oon).

For example, with respect to id_net, a CS value for the sidelink SSS maybe applied to be different from a CS value for a downlink SSS. Also,with respect to id_oon, a CS value for the sidelink PSS may be appliedto be different from a CS value for a downlink PSS.

The example of the present example of applying a CS value for thesidelink PSS to be different from a CS value for the downlink PSS withrespect to id_oon and using a portion of CS values for the downlink PSSas a CS value for the sidelink PSS with respect to id_net corresponds toexample C1+C2-PSS among the aforementioned combinations of examples A1,B1, C1, and C2 and thus, a further description is omitted.

Also, the example of applying a CS value for the sidelink SSS to bedifferent from a CS value for the downlink SSS with respect to id_netand using a portion of CS values for the downlink SSS as a CS value forthe sidelink SSS with respect to id_oon corresponds to example C1+C2-SSSamong the aforementioned combinations of examples A1, B1, C1, and C2 andthus, a further description is omitted. Here, examples of the presentexample about a CS value of the sidelink SSS are described.

For example, as shown in the above Equation 25, if N_(ID) ⁽²⁾=1 (i.e.,in the case of id_oon), m₀={0, 5, 10, 15, 20, 25, 30, 35, 40}, and ifN_(ID) ⁽²⁾=0 (i.e., in the case of id_net), m₀={0+k, 5+k, 10+k, 15+k,20+k, 25+k, 30+k, 35+k, 40+k}. Also, m₁={0, 1, . . . , 111} may be usedfor m₀={0, 0+k, 5, 5+k, 10, 10+k, 15, 15+k, 20, 20+k, 25, 25+k, 30,30+k, 35, 35+k, 40, 40+k}. Therefore, a number of possible combinationsof m₀ and m₁ may correspond to a total of 2016 (=18*112) SLIDs. Here,although a value of k=45 may be given, it is provided as an exampleonly. For example, k may be a value that satisfies 40+k<112 amongmultiples of 5, greater than 40 (e.g., one of k={45, 50, 55, . . . ,70}).

Examples A2 and B1

A physical layer sidelink synchronization identity set may be definedinto three types, that is, id_net_1, id_net_2, and id_oon, and each ofid_net_1, id_net_2, and id_oon may include 168 sequences and may bedefined as follows:

id_net_1={0,1, . . . ,167}

id_net_2={168,169, . . . ,335}

id_oon={336,337, . . . ,503}

N _(ID) ^(SL)={0,1, . . . ,503}

N _(ID) ⁽¹⁾ =N _(ID) ^(SL)mod168

N _(ID) ⁽²⁾=int(N _(ID) ^(SL)/168),N _(ID) ⁽²⁾={0,1,2}

Examples A2, B1, and C1

A primitive polynomial and an initialization value for a sidelink PSSmay be applied to be identical to those for a downlink PSS. Here, a CSvalue for the sidelink PSS may be applied to be different from a CSvalue for the downlink PSS. The present example corresponds to exampleC1-PSS among the aforementioned combinations of examples A1, B1, and C1and thus, a further description is omitted.

As shown in the above Equation 10, the CS value for the sidelink PSS maybe defined as CS=0+k if N_(ID) ⁽²⁾=0, CS=43+k if N_(ID) ⁽²⁾=1, andCS=86+k if N_(ID) ⁽²⁾=2. Here, although a value of k=21 or 22 may begiven, it is provided as an example only.

A primitive polynomial and an initialization value for a sidelink SSSmay be applied to be identical to those for a downlink SSS. Here, a CSvalue for the sidelink SSS may use a portion of CS values for thedownlink SSS. The present example corresponds to example C1-SSS amongthe aforementioned combinations of examples A1, B1, and C1 and thus, afurther description is omitted. Here, examples of the present exampleabout a CS value of the sidelink SSS are described.

For example, as shown in the above Equation 11, m₀={0, 5, 10, 15, 20,25} may be used. Here, m₁={0, 1, . . . , 111} may be used for m₀={0, 5,10} and m₁={0, 1, . . . , 55} may be used for m₀={15, 20, 25}.Therefore, a number of possible combinations of m₀ and m₁ may correspondto a total of 504 (=3*112+3*56) SLIDs.

As an additional example, as shown in the above Equation 13, m₀={0, 5,10, 15, 20, 25} and m₁={0, 1, . . . , 83} may be used. Therefore, anumber of possible combinations of m₀ and m₁ may correspond to a totalof 504 (=6*84) SLIDs.

Examples A2, B1, and C2

A primitive polynomial and an initialization value for a sidelink PSSmay be applied to be identical to those for a downlink PSS. Here, a CSvalue for the sidelink PSS may be applied to be identical to a CS valuefor the downlink PSS. That is, the CS value may be defined as CS=0 ifN_(ID) ⁽²⁾=0, CS=43 if N_(ID) ⁽²⁾=1, and CS=86 if N_(ID) ⁽²⁾=2.

A primitive polynomial and an initialization value for a sidelink SSSmay be applied to be identical to those for a downlink SSS. Here, a CSvalue for the sidelink SSS may be applied to be different from a CSvalue for the downlink SSS. The present example corresponds to exampleC2-SSS among the aforementioned combinations of examples A1, B1, and C2and thus, a further description is omitted. Here, examples of thepresent example about a CS value of the sidelink SSS are described.

For example, as shown in the above Equation 15, m₀={0+k, 5+k, 10+k,15+k, 20+k, 25+k} may be used. Here, m₁={0, 1, . . . , 111} may be usedfor m₀={0+k, 5+k, 10+k} and m₁={0, 1, . . . , 55} may be used form₀={15+k, 20+k, 25+k}. Therefore, a number of possible combinations ofm₀ and m₁ may correspond to a total of 504 (=3*112+3*56) SLIDs. Here,although a value of k=45 may be given, it is provided as an exampleonly. For example, k may be a value that satisfies 25+k<112 amongmultiples of 5, greater than 40 (e.g., one of k={45, 50, 55, . . . ,85}).

As an additional example, as shown in the above Equation 17, m₀={0+k,5+k, 10+k, 15+k, 20+k, 25+k} and m₁={0, 1, . . . , 83} may be used.Therefore, a number of possible combinations of m₀ and m₁ may correspondto a total of 504 (=3*112+3*56) SLIDs. Here, although a value of k=45may be given, it is provided as an example only. For example, k may be avalue that satisfies 25+k<112 among multiples of 5, greater than 40(e.g., one of k={45, 50, 55, . . . , 85}).

Examples A2, B1, and C3

A primitive polynomial for a sidelink PSS may use another singleprimitive polynomial (e.g., a polynomial corresponding to octal 203 ofTable 5) distinguished from a primitive polynomial applied to a downlinkPSS among first and second primitive polynomials for a sidelink SSS. Thepresent example is identical to description related to a sidelink PSSprimitive polynomial and initialization value in example C3-PSS amongthe aforementioned combinations of examples A1, B1, and C3 and thus, afurther description is omitted.

A CS value for the sidelink PSS may be defined as CS=0 if N_(ID) ⁽²⁾=0,CS=43 if N_(ID) ⁽²⁾=1, and CS=86 if N_(ID) ⁽²⁾=2.

Although a primitive polynomial and an initialization value for thesidelink SSS use the same polynomial to that for the downlink SSS, firstand second primitive polynomials may be replaced with each other. Forexample, if first and second primitive polynomials applied to thedownlink SSS are defined as polynomials corresponding to octal 221 and203 of Table 5, respectively (see Equation 9), first and secondprimitive polynomials applied to the sidelink SSS may be defined aspolynomials corresponding to octal 203 and 221 of Table 5, respectively.The present example corresponds to example C3-SSS among theaforementioned combinations of examples A1, B1, and C3 and thus, afurther description is omitted. Here, examples of the present exampleabout a CS value of the sidelink SSS will be described.

For example, as shown in the above Equation 11, m₀={0, 5, 10, 15, 20,25} may be used. Here, m₁={0, 1, . . . , 111} may be used for m₀={0, 5,10} and m₁={0, 1, . . . , 55} may be used for m₀={15, 20, 25}.Therefore, a number of possible combinations of m₀ and m₁ may correspondto a total of 504 (=3*112+3*56) SLIDs.

As an additional example, as shown in the above Equation 13, m₀={0, 5,10, 15, 20, 25} and m₁={0, 1, . . . , 83} may be used. Therefore, anumber of possible combinations of m₀ and m₁ may correspond to a totalof 504 (=6*84) SLIDs.

Examples A2, B1, and C4

In the present example, first and second primitive polynomials differentfrom those applied to a downlink SSS may be applied to a sidelink SSS.Also, one of the first and second primitive polynomials for the sidelinkSSS may be applied as a primitive polynomial for a sidelink PSS.Therefore, the first and second primitive polynomials used for thedownlink PSS and the downlink SSS and first and second primitivepolynomials used for the sidelink PSS and the sidelink SSS may notoverlap.

A primitive polynomial for the sidelink PSS may be selected from amongpolynomials belonging to the maximum connected set of Table 6. Thepresent example is identical to description related to a sidelink PSSprimitive polynomial and initialization value in example C4-PSS amongthe aforementioned combinations of examples A1, B1, and C4 and thus, afurther description is omitted.

A CS value for the sidelink PSS may be defined as CS=0 if N_(ID) ⁽²⁾=0,CS=43 if N_(ID) ⁽²⁾=1, and CS=86 if N_(ID) ⁽²⁾=2.

The same primitive polynomial as a primitive polynomial for a sidelinkPSS may be selected as a first primitive polynomial for the sidelinkSSS, and one of polynomials belonging to the same maximum connected setas that of the first primitive polynomial may be selected as a secondprimitive polynomial for the sidelink SSS. The present examplecorresponds to example C4-SSS among the aforementioned combinations ofexamples A1, B1, and C4 and thus, a further description is omitted here.Here, examples of the present example about a CS value of the sidelinkSSS are described.

For example, as shown in the above Equation 11, m₀={0, 5, 10, 15, 20,25} may be used. Here, m₁={0, 1, . . . , 111} may be used for m₀={0, 5,10}, and m₁={0, 1, . . . , 55} may be used for m₀={15, 20, 25}.Therefore, a number of possible combinations of m₀ and m₁ may correspondto a total of 504 (=3*112+3*56) SLIDs.

As an additional example, as shown in the above Equation 13, m₀={0, 5,10, 15, 20, 25} and m₁={0, 1, . . . , 83} may be used. Therefore, anumber of possible combinations of m₀ and m₁ may correspond to a totalof 540 (=6*84) SLIDs.

Examples A2 and B2

A physical layer sidelink synchronization identity set may be definedinto three types, that is, id_net_1, id_net_2, and id_oon, and each ofid_net_1, id_net_2, and id_oon may include 336 sequences and may bedefined as follows:

id_net_1={0,1, . . . ,335}

id_net_2={336,337, . . . ,503}

id_oon={504,505, . . . ,1007}

N _(ID) ^(SL)={0,1, . . . ,1007}

N _(ID) ⁽¹⁾ =N _(ID) ^(SL)mod336

N _(ID) ⁽²⁾=int(N _(id) ^(SL)/336),N _(ID) ⁽²⁾={0,1,2}

Examples A2, B2, and C1

A primitive polynomial and an initialization value for a sidelink PSSmay be applied to be identical to those for a downlink PSS. Here, a CSvalue for the sidelink PSS may be applied to be different from a CSvalue for the downlink PSS. The present example is identical todescription related to a sidelink PSS primitive polynomial andinitialization value in example C1-PSS among the aforementionedcombinations of examples A1, B1, and C1 and thus, a further descriptionis omitted.

As shown in the above Equation 10, the CS value for the sidelink PSS maybe defined as CS=0+k if N_(ID) ⁽²⁾=0, CS=43+k if N_(ID) ⁽²⁾=1, andCS=86+k if N_(ID) ⁽²⁾=2. Here, although a value of k=21 or 22 may begiven, it is provided as an example only.

A primitive polynomial and an initialization value for a sidelink SSSmay be applied to be identical to those for a downlink SSS. Here, a CSvalue for the sidelink SSS may be applied to be identical to a CS valuefor the downlink SSS.

For example, as shown in the above Equation 11, m₀={0, 5, 10, 15, 20,25, 30, 35, 40} and m₁={0, 1, . . . , 111} may be used. Therefore, anumber of possible combinations of m₀ and m₁ may correspond to a totalof 1008 (=9*112) SLIDs.

Examples A2, B2, and C2

A primitive polynomial and an initialization value for a sidelink PSSmay be applied to be identical to those for a downlink PSS. Here, a CSvalue for the sidelink PSS may be applied to be identical to a CS valuefor the downlink PSS. That is, the CS value may be defined as CS=0 ifN_(ID) ⁽²⁾=0, CS=43 if N_(ID) ⁽²⁾=1, and CS=86 if N_(ID) ⁽²⁾=2.

A primitive polynomial and an initialization value for a sidelink SSSmay be applied to be identical to those for a downlink SSS. Here, a CSvalue for the sidelink SSS may be applied to be different from a CSvalue for the downlink SSS. The present example corresponds to exampleC2-SSS among the aforementioned combinations of examples A1, B1, and C2and thus, a further description is omitted. Here, examples of thepresent example about a CS value of the sidelink SSS are described.

For example, as shown in the above Equation 15, m₀={0+k, 5+k, 10+k,15+k, 20+k, 25+k, 30+k, 35+k, 40+k} and m₁={0, 1, . . . , 111} may beused. Therefore, a number of possible combinations of m₀ and m₁ maycorrespond to a total of 1008 (=9*112) SLIDs. Here, although a value ofk=45 may be given, it is provided as an example only. For example, k maybe a value that satisfies 40+k<112 among multiples of 5, greater than 40(e.g., one of k={45, 50, 55, . . . , 70}).

Examples A2, B2, and C3

A primitive polynomial for a sidelink PSS may use another singleprimitive polynomial (e.g., a polynomial corresponding to octal 203 ofTable 5) distinguished from a primitive polynomial applied to a downlinkPSS among first and second primitive polynomials for a sidelink SSS. Thepresent example is identical to description related to a sidelink PSSprimitive polynomial and initialization value in example C3-PSS amongthe aforementioned combinations of examples A1, B1, and C3 and thus, afurther description is omitted.

A CS value for the sidelink PSS may be defined as CS=0 if N_(ID) ⁽²⁾=0,CS=43 if N_(ID) ⁽²⁾=1, and CS=86 if N_(ID) ⁽²⁾=2.

Although a primitive polynomial and an initialization value for thesidelink SSS may use the same polynomial as that for a downlink SSS,first and second primitive polynomials may be replaced with each other.For example, if first and second primitive polynomials applied to thedownlink SSS are defined as polynomials corresponding to octal 221 and203 of Table 5, respectively (see Equation 9), first and secondprimitive polynomials applied to the sidelink SSS may be defined aspolynomials corresponding to octal 203 and 221 of Table 5, respectively.The present example corresponds to example C3-SSS among theaforementioned combinations of examples A1, B1, and C3 and thus, afurther description is omitted. Here, examples of the present exampleabout a CS value of the sidelink SSS are described.

For example, as shown in the above Equation 11, m₀={0, 5, 10, 15, 20,25, 30, 35, 40} and m₁={0, 1, . . . , 111} may be used. Therefore, anumber of possible combinations of m₀ and m₁ may correspond to a totalof 1008 (=9*112) SLIDs.

Examples A2, B2, and C4

In the present example, first and second primitive polynomials differentfrom those applied to a downlink SSS may be applied to a sidelink SSS.Also, one of the first and second primitive polynomials for the sidelinkSSS may be applied as a primitive polynomial for a sidelink PSS.Therefore, first and second primitive polynomials used for a downlinkPSS and the downlink SSS and first and second primitive polynomials usedfor the sidelink PSS and the sidelink SSS may not overlap.

A primitive polynomial for the sidelink PSS may be selected from amongpolynomials belonging to the maximum connected set of Table 6. Thepresent example is identical to description related to a sidelink PSSprimitive polynomial and initialization value in example C4-PSS amongthe aforementioned combinations of examples A1, B1, and C4 and thus, afurther description is omitted.

A CS value for the sidelink PSS may be defined as CS=0 if N_(ID) ⁽²⁾=0,CS=43 if N_(ID) ⁽²⁾=1, and CS=86 if N_(ID) ⁽²⁾=2.

The same primitive polynomial as a primitive polynomial for a sidelinkPSS may be selected as a first primitive polynomial for the sidelinkSSS, and one of polynomials belonging to the same maximum connected setas that of the first primitive polynomial may be selected as a secondprimitive polynomial for the sidelink SSS. The present examplecorresponds to example C4-SSS among the aforementioned combinations ofexamples A1, B1, and C4 and thus, a further description is omitted here.Here, examples of the present example about a CS value of the sidelinkSSS are described.

For example, as shown in the above Equation 11, m₀={0, 5, 10, 15, 20,25, 30, 35, 40} and m₁={0, 1, . . . , 111} may be used. Therefore, anumber of possible combinations of m₀ and m₁ may correspond to a totalof 1008 (=9*112) SLIDs.

Examples A2 and B3

A physical layer sidelink synchronization identity set may be definedinto three types, that is, id_net_1, id_net_2, and id_oon, and each ofid_net_1, id_net_2, and id_oon may include 504 sequences and may bedefined as follows:

id_net_1={0,1, . . . ,503}

id_net_2={504,505, . . . ,1007}

id_oon={1008,1009, . . . ,1511}

N _(ID) ^(SL)={0,1, . . . ,1512}

N _(ID) ⁽¹⁾ =N _(ID) ^(SL)mod504

N _(ID) ⁽²⁾=int(N _(ID) ^(SL)/504),N _(ID) ⁽²⁾={0,1,2}

Examples A2, B3, and C1

A primitive polynomial and an initialization value for a sidelink PSSmay be applied to be identical to those for a downlink PSS. Here, a CSvalue for the sidelink PSS may be applied to be different from a CSvalue for the downlink PSS. The present example is identical todescription related to a sidelink PSS primitive polynomial andinitialization value in example C1-PSS among the aforementionedcombinations of examples A1, B1, and C1 and thus, a further descriptionis omitted.

As shown in the above Equation 10, the CS value for the sidelink PSS maybe defined as CS=0+k if N_(ID) ⁽²⁾=0, CS=43+k if N_(ID) ⁽²⁾=1, andCS=86+k if N_(ID) ⁽²⁾=2. Here, although a value of k=21 or 22 may begiven, it is provided as an example only.

A primitive polynomial and an initialization value for a sidelink SSSmay be applied to be identical to those for a downlink SSS. Here, a CSvalue for the sidelink SSS may be applied to be identical to a CS valuefor the downlink SSS.

For example, as shown in the above Equation 11, m₀={0, 5, 10, 15, 20,25, 30, 35, 40, 45, 50, 55, 60, 65, 70} may be used. Here, m₁={0, 1, . .. , 111} may be used for m₀={0, 5, 10, 15, 20, 25, 30, 35, 40, 45, 50,55} and m₁={0, 1, . . . , 55} may be used for m₀={60, 65, 70}.Therefore, a number of possible combinations of m₀ and m₁ may correspondto a total of 1512 (=12*112+3*56) SLIDs.

As an additional example, as shown in the above Equation 13, m₀={0, 5,10, 15, 20, 25, 30, 35, 40, 45, 50, 55, 60, 65, 70, 75, 80, 85} andm₁={0, 1, . . . , 83} may be used. Therefore, a number of possiblecombinations of m₀ and m₁ may correspond to a total of 1512 (=18*84)SLIDs.

Examples A2, B3, and C3

A primitive polynomial for a sidelink PSS may use another singleprimitive polynomial (e.g., a polynomial corresponding to octal 203 ofTable 5) distinguished from a primitive polynomial applied to a downlinkPSS among first and second primitive polynomials for a sidelink SSS. Thepresent example is identical to description related to a sidelink PSSprimitive polynomial and initialization value in example C3-PSS amongthe aforementioned combinations of examples A1, B1, and C3 and thus, afurther description is omitted.

A CS value for the sidelink PSS may be defined as CS=0 if N_(ID) ⁽²⁾=0,CS=43 if N_(ID) ⁽²⁾=1, and CS=86 if N_(ID) ⁽²⁾=2.

Although a primitive polynomial and an initialization value for thesidelink SSS may use the same polynomial as that for a downlink SSS,first and second primitive polynomials may be replaced with each other.For example, if first and second primitive polynomials applied to thedownlink SSS are defined as polynomials corresponding to octal 221 and203 of Table 5, respectively (see Equation 9), first and secondprimitive polynomials applied to the sidelink SSS may be defined aspolynomials corresponding to octal 203 and 221 of Table 5, respectively.The present example corresponds to example C3-SSS among theaforementioned combinations of examples A1, B1, and C3 and thus, afurther description is omitted. Here, examples of the present exampleabout a CS value of the sidelink SSS will be described.

For example, as shown in the above Equation 11, m₀={0, 5, 10, 15, 20,25, 30, 35, 40, 45, 50, 55, 60, 65, 70} may be used. Here, m₁=10, 1, . .. , 1111 may be used for m₀={0, 5, 10, 15, 20, 25, 30, 35, 40, 45, 50,55} and m₁=10, 1, . . . , 551 may be used for m₀={60, 65, 70}.Therefore, a number of possible combinations of m₀ and m₁ may correspondto a total of 1512 (=12*112+3*56) SLIDs.

As an additional example, as shown in the above Equation 13, m₀={0, 5,10, 15, 20, 25, 30, 35, 40, 45, 50, 55, 60, 65, 70, 75, 80, 85} andm₁={0, 1, . . . , 83} may be used. Therefore, a number of possiblecombinations of m₀ and m₁ may correspond to a total of 1512 (=18*84)SLIDs.

Examples A2, B3, and C4

In the present example, first and second primitive polynomials differentfrom those applied to a downlink SSS may be applied to a sidelink SSS.Also, one of the first and second primitive polynomials for the sidelinkSSS may be applied as a primitive polynomial for a sidelink PSS.Therefore, first and second primitive polynomials used for a downlinkPSS and the downlink SSS and first and second primitive polynomials usedfor the sidelink PSS and the sidelink SSS may not overlap.

A primitive polynomial for the sidelink PSS may be selected from amongpolynomials belonging to the maximum connected set of Table 6. Thepresent example is identical to description related to a sidelink PSSprimitive polynomial and initialization value in example C4-PSS amongthe aforementioned combinations of examples A1, B1, and C4 and thus, afurther description is omitted.

A CS value for the sidelink PSS may be defined as CS=0 if N_(ID) ⁽²⁾=0,CS=43 if N_(ID) ⁽²⁾=1, and CS=86 if N_(ID) ⁽²⁾=2.

The same primitive polynomial as a primitive polynomial for a sidelinkPSS may be selected as a first primitive polynomial for the sidelinkSSS, and one of polynomials belonging to the same maximum connected setas that of the first primitive polynomial may be selected as a secondprimitive polynomial for the sidelink SSS. The present examplecorresponds to example C4-SSS among the aforementioned combinations ofexamples A1, B1, and C4 and thus, a further description is omitted here.Here, examples of the present example about a CS value of the sidelinkSSS are described.

For example, as shown in the above Equation 11, m₀={0, 5, 10, 15, 20,25, 30, 35, 40, 45, 50, 55, 60, 65, 70} may be used. Here, m₁={0, 1, . .. , 111} may be used for m₀={0, 5, 10, 15, 20, 25, 30, 35, 40, 45, 50,55} and m₁={0, 1, . . . , 55} may be used for m₀={60, 65, 70}.Therefore, a number of possible combinations of m₀ and m₁ may correspondto a total of 1512 (=12*112+3*56) SLIDs.

As an additional example, as shown in Equation 13, m₀={0, 5, 10, 15, 20,25, 30, 35, 40, 45, 50, 55, 60, 65, 70, 75, 80, 85} and m₁={0, 1, . . ., 83} may be used. Therefore, a number of possible combinations of m₀and m₁ may correspond to a total of 1512 (=18*84) SLIDs.

FIG. 12 is a diagram illustrating a configuration of a first terminaldevice according to the present disclosure.

Referring to FIG. 12 , a first terminal device 1200 may include aprocessor 1210, an antenna device 1220, a transceiver 1230, and a memory1240.

The processor 1210 may perform baseband-related signal processing andmay include an upper layer processing 1211 and a physical (PHY) layerprocessing 1215. The upper layer processing 1211 may process anoperation of a medium access control (MAC) layer, a radio resourcecontrol (RRC) layer, or more upper layers. The PHY layer processing 1215may process an operation (e.g., downlink (DL) received signalprocessing, uplink (UL) transmission signal processing, sidelink (SL)transmission signal processing, etc.) of a PHY layer. The processor 1210may control the overall operation of the first terminal device 1200 inaddition to performing the baseband-related signal processing.

The antenna device 1220 may include at least one physical antenna. Ifthe antennal device 1220 includes a plurality of antennas, a multipleinput multiple output (MIMO) transmission and reception may besupported. The transceiver 1230 may include a radio frequency (RF)transmitter and an RF receiver. The memory 1240 may store operationprocessed information of the processor 1210 and software, an operatingsystem (OS), an application, etc., associated with an operation of thefirst terminal device 1200, and may include a component, such as abuffer.

The processor 1210 of the first terminal device 1200 may be configuredto implement an operation of a first UE or an SL transmitting UE in theexamples described herein.

For example, the upper layer processing 1211 of the processor 1210 ofthe first terminal device 1200 may receive a setting and a parameterabout a sidelink synchronization signal from a base station and mayforward the same to the PHY layer processing 1215.

The PHY layer processing 1215 may include a sidelink synchronizationsignal sequence generator 1216 and an SS block generator 1217.

The sidelink synchronization signal sequence generator 1216 maydetermine values of N_(ID) ⁽¹⁾ and N_(ID) ⁽²⁾ based on a sidelinkidentity (SLID) or N_(ID) ^(SL).

Here, various examples of the present disclosure may include a case inwhich a physical layer sidelink synchronization identity set isconfigured using two types (e.g., id_net and id_oon in the example ofFIG. 9 ) or a case in which the physical layer sidelink synchronizationidentity set is configured using three types (e.g., id_net_1, id_net_2,and id_oon in the example of FIG. 9 ).

Also, various examples of the present disclosure may include a case inwhich each type of the physical layer sidelink synchronization identityset (e.g., each of id_net and id_oon, or each of id_net_1, id_net_2, andid_oon in the example of FIG. 9 ) includes 168 sequences, a case inwhich each type thereof includes 336 sequences, a case in which eachtype thereof 504 sequences, or a case in which each type thereofincludes 1008 sequences.

As described above, values of N_(ID) ⁽¹⁾ and N_(ID) ⁽²⁾ corresponding toan SLID value may be determined based on a number of types of a physicallayer sidelink synchronization identity set and a number ofsynchronization signal sequences included in each type of the identityset.

The sidelink synchronization signal sequence generator 1216 may generatean NR-primary sidelink synchronization signal (NR-PSSS) sequence byapplying a first initialization value to a first primitive polynomial.Also, the transmitting UE may determine a cyclic shift (CS) value to beapplied to the generated NR-PSSS sequence based on the value of N_(ID)⁽²⁾ and may apply CS to an NR-PSSS.

Here, in various examples of the present disclosure, an NR sidelinksynchronization signal sequence may be distinguished from an NR downlinksynchronization signal sequence by applying a first primitive polynomialused to generate an NR-PSSS sequence to be distinguished from a firstprimitive polynomial applied to the NR downlink synchronization signalsequence.

Also, in various examples of the present disclosure, an NR sidelinksynchronization signal sequence may be distinguished from an NR downlinksynchronization signal sequence by applying a CS value for an NR-PSSSdistinguished from a CS value applied to the NR downlink synchronizationsignal sequence.

The sidelink synchronization signal sequence generator 1216 may generatea first NR-secondary sidelink synchronization signal (NR-SSSS) sequenceby applying a second initialization value to the first primitivepolynomial and may generate a second NR-SSSS sequence by applying thesecond initialization value to a second primitive polynomial.

Here, in various examples of the present disclosure, an NR sidelinksynchronization signal sequence may be distinguished from an NR downlinksynchronization signal sequence by applying at least one of first andsecond primitive polynomials used to generate an NR-SSSS sequence to bedistinguished from at least one of first and second primitivepolynomials applied to the NR downlink synchronization signal sequence.

The sidelink synchronization signal sequence generator 1216 maydetermine a CS value to be applied to the first NR-SSSS sequence basedon the values of N_(ID) ⁽¹⁾ and N_(ID) ⁽²⁾ and may apply CS to the firstNR-SSSS. Also, the transmitting UE may determine a CS value to beapplied to the generated second NR-SSSS sequence based on the values ofN_(ID) ⁽¹⁾ and N_(ID) ⁽²⁾ and may apply CS to the second NR-SSSSsequence.

Here, in various examples of the present disclosure, an NR sidelinksynchronization signal sequence may be distinguished from an NR downlinksynchronization signal sequence by applying at least one of a CS valuefor a first NR-SSSS sequence and a CS value for a second NR-SSSSsequence to be distinguished from a CS value applied to the NR downlinksynchronization signal sequence.

The sidelink synchronization signal sequence generator 1216 may generatean NR-PSSS modulation symbol by performing BPSK modulation of theNR-PSSS sequence to which the CS is applied. Also, the transmitting UE7may generate an NR-PSSS modulation symbol by multiplying a BPSKmodulation result of the first NR-SSSS sequence to which the CS isapplied by a BPSK modulation result of the second NR-SSSS sequence towhich the CS is applied.

The SS block generator 1217 may map the NR-PSSS modulation symbol onconsecutive subcarriers on a frequency in a single symbol within asingle SS block and may map the NR-SSSS modulation symbol on consecutivesubcarriers on the frequency in another symbol within the single SSblock. The PHY layer processing 1215 may generate and transmit asidelink synchronization signal based on a modulation symbol mapped ontime-frequency resources.

FIG. 13 is a diagram illustrating a configuration of a second terminaldevice according to the present disclosure.

Referring to FIG. 13 , a second terminal device 1300 may include aprocessor 1310, an antenna device 1320, a transceiver 1330, and a memory1340.

The processor 1310 may perform baseband-related signal processing andmay include an upper layer processing 1311 and a PHY layer processing1315. The upper layer processing 1311 may process an operation of a MAClayer, an RRC layer, or more upper layers. The PHY layer processing 1315may process an operation (e.g., DL received signal processing, ULtransmission signal processing, SL received signal processing, etc.) ofa PHY layer. The processor 1310 may control the overall operation of thesecond terminal device 1300 in addition to performing baseband-relatedsignal processing.

The antenna device 1320 may include at least one physical antenna. Ifthe antenna device 1320 includes a plurality of antennas, MIMOtransmission and reception may be supported. The transceiver 1330 mayinclude an RF transmitter and an RF receiver. The memory 1340 may storeoperation processed information of the processor 1310, software, an OS,an application, etc., associated with an operation of the secondterminal device 1300, and may include a component, such as a buffer.

The processor 1310 of the second terminal device 1300 may be configuredto implement an operation of a second UE or an SL receiving UE in theexamples described herein.

The upper layer processing 1311 of the processor 1310 of the secondterminal device 1300 may receive a setting and a parameter about asidelink synchronization signal from a base station and may forward thesame to the PHY layer processing 1315.

The PHY layer processing 1315 may include an SS block processing 1316and a sidelink synchronization signal sequence processing 1317.

The SS block processing 1316 may receive an SS block from the firstterminal device 1200. The SS block processing 1316 may detect, from asingle symbol within a single SS block, an NR-PSSS modulation symbolmapped on consecutive subcarriers on a frequency and may detect, fromanother symbol within the single SS block, an NR-SSSS modulation symbolmapped on consecutive subcarriers on the frequency.

The sidelink synchronization signal sequence processing 1317 maydetermine an NR-PSSS sequence to which CS is applied from the detectedNR-PSSS modulation symbol. Also, the sidelink synchronization signalsequence processing 1317 may determine a first NR-SSSS sequence to whichthe CS is applied and a second NR-SSSS sequence to which the CS isapplied from the detected NR-SSSS modulation symbol.

The sidelink synchronization signal sequence processing 1317 maycalculate a value of N_(ID) ⁽²⁾ from a first primitive polynomial and aCS value applied to the determined NR-PSSS sequence.

Here, in various examples of the present disclosure, an NR sidelinksynchronization signal sequence may be distinguished from an NR downlinksynchronization signal sequence by applying a first primitive polynomialused to generate an NR-PSSS sequence to be distinguished from a firstprimitive polynomial applied to an NR downlink synchronization signalsequence.

Also, in various examples of the present disclosure, an NR sidelinksynchronization signal sequence may be distinguished from an NR downlinksynchronization signal sequence by applying a CS value for an NR-PSSS tobe distinguished from a CS value applied to the NR downlinksynchronization signal sequence.

The sidelink synchronization signal sequence processing 1317 may bepre-aware of a first primitive polynomial and a candidate CS valueapplicable to generate the NR-PSSS sequence and thus, may verify a CSvalue applied to a corresponding NR-PSSS from the determined NR-PSSSsequence and may calculate a value of N_(ID) ⁽²⁾ from the verified CSvalue.

The sidelink synchronization signal sequence processing 1317 maycalculate a value of N_(ID) ⁽¹⁾ from the CS value applied to thedetermined first NR-SSSS sequence and the CS value applied to the secondNR-SSSS sequence.

Here, in various examples of the present disclosure, an NR sidelinksynchronization signal sequence may be distinguished from an NR downlinksynchronization signal sequence by applying at least one of first andsecond primitive polynomials used to generate an NR-SSSS sequence to bedistinguished from at least one of first and second primitivepolynomials applied to the NR downlink synchronization signal sequence.

Also, in various examples of the present disclosure, an NR sidelinksynchronization signal sequence may be distinguished from an NR downlinksynchronization signal sequence by applying at least one of a CS valuefor a first NR-SSSS sequence and a CS value for a second NR-SSSSsequence to be distinguished from a CS value applied to the NR downlinksynchronization signal sequence.

The sidelink synchronization signal sequence processing 1317 may bepre-aware of first and second primitive polynomials and a candidate CSvalue applicable to generate the first and second NR-SSSS sequences andthus, may verify a CS value applied to each NR-PSSS from each of thefirst and second NR-SSSS sequences and may calculate the value of N_(ID)⁽¹⁾ from the verified CS value and the value of N_(ID) ⁽²⁾.

The sidelink synchronization signal sequence processing 1317 maydetermine an SLID (or N_(ID) ^(SL)) from the calculated values of N_(ID)⁽¹⁾ and N_(ID) ⁽²⁾.

Here, various examples of the present disclosure may include a case inwhich a physical layer sidelink synchronization identity set isconfigured using two types (e.g., id_net and id_oon in the example ofFIG. 9 ) or a case in which the physical layer sidelink synchronizationidentity set is configured using three types (e.g., id_net_1, id_net_2,and id_oon in the example of FIG. 9 ).

Also, various examples of the present disclosure may include a case inwhich each type of the physical layer sidelink synchronization identityset (e.g., each of id_net and id_oon, or each of id_net_1, id_net_2, andid_oon in the example of FIG. 9 ) includes 168 sequences, a case inwhich each type thereof includes 336 sequences, a case in which eachtype thereof includes 504 sequences, or a case in which each typethereof includes 1008 sequences.

The sidelink synchronization signal sequence processing 1317 may bepre-aware of a number of types of a physical layer sidelinksynchronization identity set and a number of synchronization signalsequences included in each type of the identity set and thus, maydetermine an SLID value corresponding to the values of N_(ID) ⁽¹⁾ andN_(ID) ⁽²⁾.

The aforementioned description made in the foregoing examples of thepresent disclosure may apply alike to an operation of the first terminaldevice 1200 and the second terminal device 1300 and thus, a furtherdescription is omitted.

In the example methods described above, processes are described as aseries of operations based on a flowchart, aspects of the presentdisclosure are not limited to the illustrated order or sequence. Someoperation may be processed in a different order or may be processedsubstantially simultaneously. Further, it will be understood that theillustrated operations in a flowchart do not necessarily exclude otheroperations, other operations may be included and one or more operationsmay be omitted without departing from the spirit and scope of thepresent disclosure.

Various embodiments of the present disclosure are not all the possiblecombinations and are to explain the representative aspects of thepresent disclosure. Thus, it will be apparent that the descriptions madein various embodiments may apply independently or combination of atleast two thereof.

Also, various embodiments of the present disclosure may be implementedby hardware, firmware, software, or combinations thereof. In the case ofimplementation by hardware, the embodiments may be implemented by one ormore application-specific integrated circuits (ASICs), digital signalprocessors (DSPs), digital signal processing devices (DSPDs),programmable logic devices (PLDs), field programmable gate arrays(FPGAs), general processors, controllers, microcontrollers,microprocessors, etc.

The scope of the present disclosure includes software ormachine-executable instructions (e.g., OS, application, firmware,program, etc.) such that operations of the method of the variousembodiments may be executed on an apparatus or a computer, and anon-transitory computer-readable medium storing such software orinstructions to be executable on an apparatus or a computer.

What is claimed is:
 1. A wireless user device comprising: a processor;and a memory storing instructions that, when executed by the processor,cause the wireless user device to: determine a first sidelink identity(SLID) parameter and a second SLID parameter; determine a firstparameter associated with a sidelink primary synchronization signal,based on: a second parameter; an offset value; and a multiple of thesecond SLID parameter; determine, based on the first parameter, asequence for the sidelink primary synchronization signal; and transmit,to a second wireless user device, at least one sidelink synchronizationsignal comprising the sidelink primary synchronization signal andcomprising a sidelink secondary synchronization signal.
 2. The wirelessuser device of claim 1, wherein the instructions, when executed by theprocessor, cause the wireless user device to determine the firstparameter based on a sum of the second parameter, the offset value, andthe multiple of the second SLID parameter.
 3. The wireless user deviceof claim 1, wherein the second parameter is integer n, where 0≤n<N, andN is a preconfigured integer corresponding to a length of the sequencefor the sidelink primary synchronization signal, and wherein theinstructions, when executed by the processor, cause the wireless userdevice to determine the first parameter based on a modulo operation byusing: a sum of the second parameter, the offset value, and the multipleof the second SLID parameter; and N.
 4. The wireless user device ofclaim 1, wherein the second SLID parameter comprises either a firstvalue indicating that the wireless user device is synchronized with abase station or a second value indicating that the wireless user deviceis not synchronized with a base station.
 5. The wireless user device ofclaim 1, wherein the sequence comprises d_(PSS)(n), whereind_(PSS)(n)=1−2x(m), m=(n+p·N_(ID) ⁽²⁾+k) mod N, k is the offset value, pis an integer value, and N_(ID) ⁽²⁾ is the second SLID parameter, andp·N_(ID) ⁽²⁾ is the multiple of the second SLID parameter, where 0≤n<N,and N is a preconfigured integer.
 6. The wireless user device of claim5, wherein p is equal to 43, wherein k is equal to 21 or 22, and whereinN is
 127. 7. The wireless user device of claim 1, wherein the multipleof the second SLID parameter is p·N_(ID) ⁽²⁾, and N_(ID) ⁽²⁾ is thesecond SLID parameter, and wherein k is the offset value, and${k = {\left\lfloor \frac{p}{2} \right\rfloor{or}\left\lceil \frac{p}{2} \right\rceil}},$where $\left\lfloor \frac{p}{2} \right\rfloor$ is the floor of$\frac{p}{2},$ and $\left\lceil \frac{p}{2} \right\rceil$ is the ceilingof $\frac{p}{2}.$
 8. The wireless user device of claim 1, wherein themultiple of the second SLID parameter is p·N_(ID) ⁽²⁾, and N_(ID) ⁽²⁾ isthe second SLID parameter, and wherein k is the offset value and is oneof integer values closest to one half of p.
 9. The wireless user deviceof claim 1, wherein the first SLID parameter is selected from a firstset {0, 1, 2, . . . , 333, 334, 335}, and wherein the second SLIDparameter is selected from a second set {0, 1}.
 10. The wireless userdevice of claim 1, wherein the instructions, when executed by theprocessor, cause the wireless user device to: generate, based on thesequence for the sidelink primary synchronization signal, the sidelinkprimary synchronization signal; and generate, based on the first SLIDparameter and the second SLID parameter, the sidelink secondarysynchronization signal.
 11. The wireless user device of claim 1, whereinthe instructions, when executed by the processor, cause the wirelessuser device to: receive, from a base station, at least one downlinksynchronization signal block comprising a primary synchronization signal(PSS) and comprising a secondary synchronization signal (SSS), andwherein the first SLID parameter and the second SLID parameter areassociated with an SLID of the wireless user device for sidelinkcommunication between wireless user devices.
 12. The wireless userdevice of claim 1, wherein the instructions, when executed by theprocessor, cause the wireless user device to: determine a sequence forthe sidelink secondary synchronization signal, based on: a first valueassociated with the first SLID parameter and associated with the secondSLID parameter; and a second value associated with the first SLIDparameter, and wherein the first SLID parameter and the second SLIDparameter are associated with an SLID of the wireless user device forsidelink communication between wireless user devices.
 13. A wirelessuser device comprising: a processor; and a memory storing instructionsthat, when executed by the processor, cause the wireless user device to:receive a sidelink primary synchronization signal and a sidelinksecondary synchronization signal, wherein the sidelink secondarysynchronization signal is associated with a sidelink identity (SLID)comprising a first SLID parameter and a second SLID parameter;determine, based on the sidelink primary synchronization signal, thesecond SLID parameter, wherein a sequence for the sidelink primarysynchronization signal is associated with a first parameter that isbased on: a second parameter; an offset value; and a multiple of thesecond SLID parameter; and determine, based on the second SLID parameterand based on the sidelink secondary synchronization signal, the firstSLID parameter.
 14. The wireless user device of claim 13, wherein theinstructions, when executed by the processor, cause the wireless userdevice to: determine, based on the first parameter, a sequence for asecond sidelink primary synchronization signal; and transmit, to asecond wireless user device, the second sidelink primary synchronizationsignal.
 15. The wireless user device of claim 14, wherein theinstructions, when executed by the processor, cause the wireless userdevice to: generate, based on the first SLID parameter and the secondSLID parameter, a second sidelink secondary synchronization signal; andtransmit, to the second wireless user device, the second sidelinksecondary synchronization signal.
 16. The wireless user device of claim13, wherein the instructions, when executed by the processor, cause thewireless user device to determine the first parameter based on a sum ofthe second parameter, the offset value, and the multiple of the secondSLID parameter.
 17. The wireless user device of claim 13, wherein thesecond parameter is integer n, where 0≤n<N, and N is a preconfiguredinteger corresponding to a length of the sequence for the sidelinkprimary synchronization signal, and wherein the instructions, whenexecuted by the processor, cause the wireless user device to determinethe first parameter based on a modulo operation by using: a sum of thesecond parameter, the offset value, and the multiple of the second SLIDparameter; and N.
 18. The wireless user device of claim 13, wherein thesecond SLID parameter comprises either a first value indicating that thewireless user device is synchronized with a base station or a secondvalue indicating that the wireless user device is not synchronized witha base station.
 19. The wireless user device of claim 13, wherein theinstructions, when executed by the processor, cause the wireless userdevice to: determine the sequence, wherein the sequence comprisesd_(PSS)(n), wherein d_(PSS)(n)=1−2x(m), m=(n+p·N_(ID) ⁽²⁾+k) mod N, k isthe offset value, p is an integer value, and N_(ID) ⁽²⁾ is the secondSLID parameter, and p·N_(ID) ⁽²⁾ is the multiple of the second SLIDparameter, where 0≤n<N, and N is a preconfigured integer.
 20. Thewireless user device of claim 19, wherein p is equal to 43, wherein k isequal to 21 or 22, and wherein N is
 127. 21. The wireless user device ofclaim 13, wherein the multiple of the second SLID parameter is p·N_(ID)⁽²⁾, where N_(ID) ⁽²⁾ is the second SLID parameter, and wherein k is theoffset value, and${k = {\left\lfloor \frac{p}{2} \right\rfloor{or}\left\lceil \frac{p}{2} \right\rceil}},$where $\left\lfloor \frac{p}{2} \right\rfloor$ is the floor of$\frac{p}{2},$ and $\left\lceil \frac{p}{2} \right\rceil$ is the ceilingof $\frac{p}{2}.$
 22. The wireless user device of claim 13, wherein themultiple of the second SLID parameter is p·N_(ID) ⁽²⁾, where N_(ID) ⁽²⁾is the second SLID parameter, and wherein k is the offset value and isone of integer values closest to one half of p.
 23. The wireless userdevice of claim 13, wherein the first SLID parameter is selected from afirst set {0, 1, 2, . . . , 333, 334, 335}, and wherein the second SLIDparameter is selected from a second set {0, 1}.